WO1995004770A1

WO1995004770A1 - Process for producing polycarbonate

Info

Publication number: WO1995004770A1
Application number: PCT/JP1994/001303
Authority: WO
Inventors: Shigeki Kuze
Original assignee: Idemitsu Petrochemical Co., Ltd.
Priority date: 1993-08-09
Filing date: 1994-08-05
Publication date: 1995-02-16

Abstract

A process for producing a polycarbonate by the transesterification between a dihydroxy compound and a carbonic diester with a reduced amount of the catalyst to be used in a short time at a good productivity, wherein the dihydroxy compound or the diester is contacted with an active-hydrogen-containing nitrogenous heterocyclic compound and/or a metallic compound as the catalyst, or use is made of an active-hydrogen-containing nitrogenous heterocyclic compound, a metallic compound and a nitrogenous basic organic compound as the catalyst. The obtained polycarbonate is coloration-free and excellent in, e.g., hydrolysis resistance.

Description

Description a Polycarbonate manufacturing method

The present invention relates to a method for producing polycarbonate used in the fields of electricity, electronics and automobiles. More specifically, the present invention relates to a method for producing polycarbonate capable of providing high-quality polycarbonate with high productivity. Background art

Polycarbonate is an engineering plastic with excellent transparency, heat resistance and impact resistance, and is a resin widely used in the industrial field today. As a method for producing polycarbonate, an interface method in which an aromatic dihydroxy compound such as bisphenol A is directly reacted with phosgene, or an aromatic dihydroxy conjugate such as bisphenol A and a carbonate diester such as diphenyl carbonate are melted. A melting method in which transesterification is performed in a state is known.

However, in the interfacial method, toxic phosgene must be used in the production process, the equipment is corroded by by-product chlorine-containing compounds such as hydrogen chloride and sodium chloride, and sodium hydroxide remaining in the resin. There are problems such as difficulty in separating impurities that adversely affect the physical properties of the polymer. On the other hand, the melting method has the advantages of not having the above-mentioned adverse effects on the environment as compared with the interface method, and has the advantage that polycarbonate can be produced at low cost. 3 1 0. There was a problem that the coloring was not lost because the reaction was carried out at a high temperature of C for a long time. In addition, a basic catalyst is often used, and there is a problem that the obtained polymer has poor hydrolysis resistance.

In the melting method, in order to prevent coloring, a method using a specific catalyst (Japanese Patent Publication No. Sho 61-39792, Japanese Patent Application Laid-Open No. Sho 63-23036, etc.) A method of adding an antioxidant (Japanese Patent Application Laid-Open Nos. No. 15 8 7 19), a method using a twin-screw vented kneading extruder at the latter stage of the reaction (Japanese Patent Application Laid-Open No. 61-62522, etc.), a method using a horizontal stirring polymerization tank (JP

2-1 5 392 5) has been proposed, but it has not been completely solved yet.

Further, in order to improve the hydrolysis resistance of the obtained polycarbonate, it has been conventionally known to neutralize with an acid such as dimethyl sulfate, and recently, neutralization with an acid such as p-toluenesulfonic acid. For example, a technique for neutralizing an excess acid with an epoxy compound (Japanese Patent Laid-Open No. 4-175,368, etc.) is known, but it has not been completely solved yet. Disclosure of the invention

An object of the present invention is to provide a method for producing a polycarbonate which has a small amount of residual catalyst in a polymer and is capable of producing a polycarbonate having excellent quality such as coloring property and hydrolysis resistance with good productivity. With the goal.

The present inventors have conducted intensive studies in order to achieve the above object, and as a result, when producing a polycarbonate by a transesterification method, an active hydrogen-containing nitrogen-containing heterocyclic compound, a metal compound and, if necessary, a basic compound as a catalyst. It has been found that the above object can be achieved by using a nitrogen-containing organic compound, and the present invention has been completed.

That is, the present invention uses (A) an active hydrogen-containing nitrogen-containing heterocyclic compound and (B) a metal compound as catalysts, and produces a polycarbonate by a transesterification reaction between a dihydroxy compound as a monomer raw material and a carbonic acid diester. In this regard, the present invention provides a method for producing polycarbonate, in which the dihydroxy compound or the carbonic acid diester is mixed with the active hydrogen-containing nitrogen-containing heterocyclic compound and Z or the metal compound in advance and contacted.

Further, the present invention relates to a method for producing a polycarbonate by transesterification from a dihydroxy compound and a carbonic acid diester, wherein (A) an active hydrogen-containing nitrogen-containing compound, (B) a metal compound, and (C) a nitrogen-containing basic compound. An object of the present invention is to provide a method for producing polycarbonate using an organic compound as a catalyst. BEST MODE FOR CARRYING OUT THE INVENTION

The dihydroxy compound used in the present invention is not particularly limited, and various dihydroxy compounds including conventionally known ones can be used.In addition, only one dihydroxy compound may be used alone, or two dihydroxy compounds may be used. The above may be used in combination. Here, examples of the dihydroxy compound include an aromatic dihydroxy compound, an aliphatic dihydroxy compound, a bisester of these compounds, and carbonates.

Examples of the aromatic dihydroxy compound suitably used in the present invention include, for example, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxy-1-2,2′-dimethylbiphenyl, 4,4′-dihi Dihydroxybiphenyl, such as droxy-1,3'-dimethylbiphenyl, 4,4'dihydroxy-3,3'-dicyclohexylbiphenyl, 3,3'-difluoro-4,4'-dihydroxybiphenyl Bis (4-hydroxyphenyl) ether, bis (3-fluoro-4-hydroxyxyphenyl) ether, bis (4-hydroxy-13-methylphenyl) ether, and other bis (hydroxyaryl) ethers; 4,, 4'-Bis (hydroxylaryl) ketones such as dihydroxybenzophenone; bis (4-hydroxyphenyl) sulfide, Bis (hydroxylaryl) sulfides such as (3-methyl-14-hydroxyphenyl) sulfide; bis (4-hydroxy-1-phenyl) sulfoxide, bis (3-methyl-14-hydroxyphenyl) sulfoxide, bis Bis (hydroxyaryl) sulfoxides such as (3-phenyl 4-hydroxyphenyl) sulfoxide; bis (4-hydroxyphenyl) sulfon, bis (3-methyl-4-hydroxyphenyl) sulfone, bis (3-phenyl) Bis (hydroxyphenyl) sulfones such as 2-hydroxy-4-phenyl sulfone; bis (4-hydroxyphenyl) methane, bis (3-methyl-1-hydroxyphenyl) methane, bis (3-chloro-4-phenyl) methane Droxyphenyl) methane, bis (3,5-dibromo-1-4-) (Hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) 1-1-phenylmethane, 1,1-bis (4-hydroxy) 11-Diphenylmethane, 11-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) 1-1-phenylmethane, 11-bis (4-hydroxyphenyl) ethane, 1,1- Bis (2-tert-butyl-4-hydroxy-3-methylphenyl) ethane, 1-phenyl-1,1-bis (3-monofluoro-4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) 1-phenylene, 2- (3-methyl-14-hydroxyphenyl) 1-2- (4-hydroxyphenyl) 1-1-phenylene, 1,1-bis (4-hydroxyphenyl) 1-22 2— Trifluorophenyl, 2,2-bis (4-hydroxyphenyl) propane, 22-bis (3-methyl-14-hydroxyphenyl) propane, 22-bis (2-methyl-14-hydroxyphenyl) ) Professional. 2,2-bis (35-dimethyl-14-hydroxyphenyl) propyl. Emissions, 1 1 one-bis (2-tert-butyl one 4 - heat Dorokishi one 5- Mechirufu Eniru) flop ⁰ emissions, 2, 2- bis (3-black port one 4-arsenide Dorokishifuweniru) pro emissions, 2 2- bis (3 Furuoro one 4-arsenide Dorokishifueniru) flop ⁰ emissions, 2, 2- bis (3-promoter 4-arsenide Dorokishifueniru) propane, 2, 2-bis (3, 5-difluoro over 4 arsenide Dorokishifueniru) propane, 2, 2-bis (35-dichloro-1-hydroxyphenyl) propane, 22-bis (35-dibutene 4-hydroxyphenyl) propane, 22-bis (3-bromo-14-hydroxy-1-5-) black hole phenyl) flop ⁰ emissions, 2, 2- bis (3-arsenate mud Kishifueniru) to hexa full O b propane, 2 2- bis (3-phenylene Lou 4-arsenide Dorokishifueniru) propane, 2 2- bis (4 -Hydroxyphenyl) butane, 22-bis (3- Cyl 4-hydroxyphenyl) butane, 1,1-bis (2-butyl-1-hydroxy-5-methylphenyl) butane, 1,1-bis (2-tert-butyl-1-hydroxy-5-methylphenyl) Butane, 11-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) isobutane, Γ, 1-bis (2-tert-amyl-14-hydroxy-5-methylphenyl) butane, 22- Bis (3,5-dichloro-4-hydroxyphenyl) butane, 2,2-bis (35-dibromo-1-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -1-4-methylpentane, 4,4-bis (4-hydroxyphenyl) heptane, 1,1-bis (2-tert-petit.ru 4-hydroxy-1-5-) Bis (hydroxyaryl) alkanes such as methylphenyl) heptane, 2,2-bis (4-hydroxyphenyl) octane, 1,2-bis (4-hydroxyphenyl) ethane, and 1,1-bis (4 —Hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3 —Bis (hydroxyaryl) cycloalkanes such as cyclohexyl 4-hydroxyphenyl) cyclohexane, 1,1-bis (3-phenyl-1-hydroxyphenyl) cyclohexane Classification of bis ((hydroxyaryl) methyl such as 1,1'-bis (4-hydroxyphenyl) -p-diisopropylbenzene, 1,1'-bis (4-hydroxyphenyl) m-diisopropylbenzene } Benzenes; resorcin, 3-methylresorcin, 3-ethylresorcin, 3-propylresorcin, 3-butylresorcin, 3-tert-butylresorcinol, 3-phenylresorcinol, 3-phenylresorcinol, 3-cumylresorcinol, 2,3,4 , 6-tetrafluororesorcin, 2,3,4,6-tetrabromoresorcinol, catechol, hydroquinone, 3-methylhydroquinone, 3-ethylhydroquinone, 3-propylhydroquinone, 3-butylhydroquinone , 3-tert-butylhydroquinone, 3-phenylhydroxyquinone, 3-cumylhydridoquinone, 2,3,5 6-tetramethylhydroquinone, 2,3,4,6-tetra-tert-butylhydroquinone, 2,5-dichlorohydroquinone, 2,3,5,6-tetrafluorohydroquinone, 2,3,5, Examples thereof include unsubstituted or halogen- and alkyl-substituted dihydroxybenzenes such as 6-tetrabromohydridoquinone.

Further, specific examples of the aliphatic dihydroxy compound used in the present invention include, 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-methyljetanolamine, cyclohexane-1,3-diol, cyclohexane-1,4-diol, 1,4-dimethylolcyclohexane, p-xylylene glycol, 2, 2-bis (4-hydroxycyclohexyl) propane and the like.

Further, in the present invention, 2,2,2 ', 2'-tetrahydro 3,3,3', 3'-tetramethyl-1-1,1'-spirobilo [1H-indene] -6,6'-dihydroxy compound is used as the dihydroxy compound. It is also possible to use a spirogyi conjugate such as a diol. Alternatively, a dihydric alcohol such as a hydroxyalkyl ester of biphenyldicarboxylic acid or a hydroxyalkyl ester of bicyclohexyldicarboxylic acid may be used instead of part of the dihydroxy compound. May be used. In this case, a polyester carbonate is obtained.

The carbonic acid diester used in the present invention is not particularly limited, and various carbonic acid diesters including known ones can be used.As the carbonic acid diester, one kind may be used alone, or two or more kinds may be used in combination. Is also good.

Among them, in the present invention, an aromatic dihydroxy compound is preferably used. Examples of the carbonic diester used in the present invention include a diaryl carbonate compound, a dialkyl carbonate compound, and an alkylaryl carbonate compound. Specific examples of the diaryl carbonate compound include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, dinaphthyl carbonate, and bis (biphenylyl carbonate). Specific examples of the dialkyl carbonate compound include getyl carbonate, dimethyl carbonate, dibutyl carbonate, and dicyclohexyl carbonate. On the other hand, specific examples of the alkylaryl carbonate compound include methylphenyl carbonate, ethylphenyl carbonate, butylphenyl carbonate, and cyclohexylphenyl carbonate. Of these, diaryl carbonate compounds such as diphenyl carbonate are preferably used.

The amount of carbonic acid diester used is usually 0.1 to 1 mole of dihydroxy compound. 90 to: I. 50 mol, preferably 0.95 to 1.25 mol, more preferably 0.98 to: I. 20 mol.

If necessary, a dicarboxylic acid or a dicarboxylic acid ester may be used instead of a part of the carbonic acid diester. In this case, polyester carbonate is obtained. Examples of the dicarboxylic acid and dicarboxylic acid ester include aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, diphenyl isophthalate, diphenyl terephthalate, dichloride isophthalate, dichloride terephthalanolate; succinic acid, glutaric acid, adipic acid; Aliphatic dicarboxylic acids such as pimelic acid, speric acid, azelaic acid, sebacic acid, decandioic acid, dodecandioic acid, diphenyl sebacate, diphenyl decanniate, etc .; cyclopropanedicarboxylic acid, 1,2-cyclobutane Dicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1 , 4-cyclohexanedicarboxylic acid Diphenyl cyclopropanedicarboxylate, diphenyl 1,2-cyclobutanedicarboxylate, diphenyl 1,3-cyclobutanedicarboxylate, diphenyl 1,2-cyclopentanedicarboxylate, diphenyl 1,1,2-cyclohexanedicarboxylate, 1,3-cyclo Alicyclic dicarboxylic acids such as diphenyl hexanedicarboxylate and diphenyl 1,4-cyclohexanedicarboxylate can be mentioned. The amount of the dicarboxylic acid and the dicarboxylic acid ester used is, for example, 50 mol% or less, preferably 30 mol% or less of the ester carbonate.

As the active hydrogen-containing nitrogen-containing heterocyclic compound (A) used as a catalyst in the present invention, for example, a compound having all-keto tautomerism represented by the following formula is particularly preferably used.

Examples of such compounds having all-keto tautomerism include hydroxy-substituted nitrogen-containing heterocyclic compounds and mercapto-substituted nitrogen-containing heterocyclic compounds. Specific examples of the hydroxy-substituted nitrogen-containing heterocyclic compound include 2-hydroxypyridyl. 4-hydroxyquinoline, 2-hydroxyquinoline, 4-hydroxyquinoline, 5-hydroxyquinoline, 7-hydroxyquinoline, 1-hydroxyisoquinoline, 3-hydroxyisoquinoline, 6—Hydroxyisoquinoline, 8—Hydroxyisoquinoline, 2—Hydroxyquinoxaline, 5—Hydroxyquinoxaline, 6—Hydroxyquinoxaline, 4-Hydroxycinnoline, 5—Hydroxycinnoline, 8 —Hydroxycinnoline, 2-hydroxypyrazine, 2-hydroxypyrimidine, 4-hydroxypyrimidine, 3-hydroxypyridazine, 4-hydroxypyridazine, 2-hydroxytriazine and the like.

Specific examples of the mercapto-substituted nitrogen-containing heterocyclic compound include 2-mercaptopyridin, 4-mercaptopyridine, 2-mercaptoquinoline, 4-mercaptoquinoline, 5-mercaptoquinoline, and 7-mercaptoquinoline. 1-mercaptoisoquinoline, 3-mercaptoisoquinoline, 6-mercaptoisoquinoline, 8-mercaptoisoquinoline, 2-mercaptoquinoxaline, 5-mercaptoquinoxaline, 6-mercaptoquinoxaline, 4-1 Mercaptocinnoline, 5-mercaptocinnoline, 8-mercaptocinnoline, 2-mercaptovirazine, 2-mercaptopyrimidine, 4-mercaptopyrimidine, 3-mercaptopyridazine, 4-mercaptopyridazine, 2-mercaptotriazine, etc. Is mentioned.

Examples of the active hydrogen-containing nitrogen-containing heterocyclic compound other than those having all-keto tautomerism as described above include an amino-substituted nitrogen-containing heterocyclic compound.

Specific examples of the amino-substituted nitrogen-containing heterocyclic compound include 2-aminoviridine, 4-aminoviridine, 2-aminoquinoline, 4-aminoquinoline, 5-aminoquinoline, 7-aminoquinoline, 1-aminoisoquinoline, and 3-aminoquinoline. Aminoisoquinoline, 6-aminoisoquinoline, 8-aminoaminoquinoline, 2-aminoquinoxaline, 5-aminoquinoxaline, 6-aminoquinoxaline, 4-aminocinnoline, 5-aminocinnoline, 8-aminocinnoline, 2 —Aminovirazine, 2-aminopyrimidine, 4-aminovirimidine, 3-aminoviridazine, 4-aminoviridazine, 2-aminotriazine and the like. The nitrogen-containing heterocycle of these compounds may have a substituent such as an alkyl group, a halogen, a cyano group, a nitro group or a methoxy group. In addition, among the above various hydroxy-substituted nitrogen-containing heterocyclic compounds, mercapto-substituted nitrogen-containing heterocyclic compounds, and amino-substituted nitrogen-containing heterocyclic compounds, compounds containing a pyridine ring or a quinoline ring as the nitrogen-containing heterocycle are preferred. Used. Specific examples of particularly preferable ones include 2-hydroxypyridine, 4-hydroxypyridine, 2-hydroxyquinoline and the like. The active hydrogen-containing nitrogen-containing heterocyclic compound (A) may be used alone or in combination of two or more.

The metal compound (B), an alkali metal or alkaline earth elemental metals, oxides, hydroxides, Ami de compound, Arukora DOO, Fuwenora bets or ZnO, PbO, basic, such as Sb ₂ 0 _3, Examples include metal oxides, organic titanium compounds, soluble manganese compounds, acetates of Ca, Mg, Zn, Pb, Sn, Mn, Cd, and Co.

In particular, as the above-mentioned metal compound, a metal conjugate selected from the group consisting of a, Mg, Mn, Zn, Ti and Co is preferably used. Specific examples of such metal compounds include metal Ca, calcium oxide, calcium hydroxide, calcium amide, calcium alcoholate, calcium phenolate, calcium oxide, metal Mg, magnesium oxide, and water. Examples include magnesium oxide, magnesium amide, magnesium alcoholate, magnesium phenolate, magnesium acetate, manganese acetate, zinc oxide, zinc acetate, an organic titanium compound, and cobalt acetate. These metal compounds (B) can be used alone or in combination of two or more.

When the two components of (A) the active hydrogen-containing nitrogen-containing heterocyclic compound and (B) the metal compound are used as catalysts, the use of the active hydrogen-containing nitrogen-containing heterocyclic compound of (A) is based on 1 mol of the dihydroxy compound. Te, usually, 10 ^7-1 mol, preferably ^10-6 ~ ^10-1 mole, more preferably 10- ⁵ to ^10-mole. If the amount is too small, the effect of improving the reaction rate may be insufficient, and if the amount is too large, the cost may be increased.

The amount of the metal compound (B) is based on 1 mole of the dihydroxy compound. Usually, 1 0 ^8-1 0 ² mol, preferably 1 0 - ⁷ to 1 0 ³ mol, more preferably 5 X 1 0 ~ 5 X 1 0- 4 mols. If the amount is less than 10 to ⁸ mol, the effect of improving the reaction rate may be insufficient. If the amount is too large, the cost may be increased.

The above proportion of the two catalyst components, (A) an active hydrogen-containing nitrogen-containing heterocyclic reduction Gobutsuno (B) metal compound (molar ratio) is usually 1 0 ⁴ to 1 0 ^3, preferably 1 0 ³ -10 0, more preferably 5 × 10 ² -1.

When the two components of (A) the active hydrogen-containing nitrogen-containing heterocyclic compound and (B) the metal compound are used as catalysts, one of the following pretreatment steps is performed before the transesterification reaction between the dihydroxy compound and the carbonic acid diester. The monomer raw material, that is, the dihydroxy compound or the carbonic acid diester is mixed with at least one of the catalyst components, that is, the active hydrogen-containing nitrogen-containing heterocyclic compound and / or the metal compound, and brought into contact with each other. By preliminarily bringing the catalyst into contact with the monomer raw material before performing the transesterification reaction, the amount of the catalyst remaining in the polycarbonate can be effectively reduced, and the polycondensation reaction can be rapidly carried out. You can let it go. In particular, it is preferable to contact the dihydroxy compound with the metal compound.

The contacting time is not particularly limited, but usually 10 minutes to 3 hours is sufficient, and preferably 15 minutes to 1 hour. If the contact time is less than 10 minutes, the effect of improving the reaction rate in the transesterification reaction may be insufficient.On the other hand, if the contact time is too long, the time required for the entire polycarbonate production process becomes longer, This will hinder productivity.

The temperature at the time of the contact is usually preferably 100 to 250 ° C, more preferably 100 to 200 ° C. If the temperature is lower than 100 ° C, the effect of improving the reaction rate in the transesterification reaction may be insufficient.If the temperature exceeds 250 ° C, the decomposition of the monomer component used for the contact, that is, the dihydroxy compound or the carbonic acid diester is performed. May occur.

This contact is preferably performed by stirring a mixture of one of the monomer raw materials and at least one of the catalyst components in an atmosphere of an inert gas such as nitrogen. Then, usually, the remaining catalyst and the monomer raw material are added to the mixture after the pretreatment step, and a transesterification reaction is performed. For example, when the dihydroxy compound is contacted with the metal compound in the pretreatment step, after the contact is completed, a diester carbonate and an active hydrogen-containing nitrogen-containing heterocyclic compound are added to the mixture of the dihydroxy compound and the metal compound, Perform transesterification.

In addition, the present inventor further provides (C) a nitrogen-containing basic organic compound as a catalyst in addition to (A) an active hydrogen-containing nitrogen-containing heterocyclic compound and (B) a metal compound, to thereby provide the above-mentioned pretreatment. It has been found that even without performing a step, a polycarbonate having excellent quality and substantially not containing a catalyst in polycarbonate can be produced with high productivity.

Specific examples of the nitrogen-containing basic organic compound (C) include fatty acids such as trimethylamine, triethylamine, tripropylamine, triptylamine, tripentylamine, trihexylamine, and dimethylpentylamine. And aromatic tertiary amine compounds such as aromatic tertiary amine compounds and triphenylamine.

In addition, N, N-dimethyl-14-aminoviridine, N, N-getyl-41-aminoviridine, 4-pyrrolidinopyridine, 2-methoxypyridine, 4-methoxypyridine, 2-dimethylaminoimidazole, 2-dimethylaminopyridine Examples include unsubstituted or dialkylamino compounds such as methoxyimidazole, imidazole, 2-methylimidazole, 4-methylimidazole, and diazabicyclooctane (DABCO). Further, tetramethylammonium Niu Muhi Dorokishido (Me ₄ NOH), tetraethyl Anmoniumuhi Dorokishido (E t ₄ NOH), tetra Petit Ruan monitor © Muhi Doroki Sid (Bu ₄ NOH :), trimethylbenzylammonium ammonium Niu Muhi Dorokishi de [C ₆ H ₅ CH ₂ (Me) 3NOH] and the like, and ammonium hydroxide having an alkyl, aryl, or alkylaryl group.

Furthermore, tetramethylammonium Niu arm borohydride high dry de (Me _₄ NBH _4), tetrabutylammonium Niu arm borohydride high dry de (B u _₄ NBH _4), tetrabutylammonium Umutetorafuwe two Ruporeto (Bu _₄ NBPh _4), tetramethylammonium A basic salt of boric acid such as ammonium nitrate sulfate (Me ₄ NBPh ₄ ) may be mentioned. Among these nitrogen-containing basic organic conjugates, for example, trihexylamine, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetramethylammoniumborohydride, tetramethylammonium hydroxide Butyl ammonium borohydride and N, N-dimethyl-4-aminoviridine are preferred. Specific examples of particularly preferred nitrogen-containing basic organic conjugates include tetramethylammonium hydroxide, tetramethylammoniumborohydride, tetrabutylammoniumborohydride, and N, N-dimethyl. 1-41 amino pyridine.

These (C) nitrogen-containing basic organic compounds may be used alone or in combination of two or more. The amount of the nitrogen-containing basic organic compounds for dihydroxy compound 1 molar, normally, 10- ^8-10 moles, preferably ^10-7 to ^10-3 mol, more preferably 10 ⁶ to 5 x 10- ⁴ moles. If the amount is too small, the effect of improving the reaction rate may be insufficient, and if the amount is too large, the cost may be increased.

In the present invention, the nitrogen-containing heterocyclic compound having active hydrogen is excluded from the nitrogen-containing basic organic compound (C).

When used as a nitrogen-containing basic organic compound is also a catalyst of the above (C), the amount of active hydrogen-containing nitrogen-containing heterocyclic compounds (A) with respect to dihydroxy compound 1 mole, usually, 10- ⁸ ~: I mol, preferably ^10-7 to ^10-1 mol, more preferably 1 0 ⁶ ~ ^10-2 mol. If the amount is too small, the effect of improving the reaction speed may be insufficient, and if the amount is too large, the cost increases. The amount of metal compound (B) for the dihydric de proxy Compound 1 mol, usually 10- ⁸ to ^10-2 mol, preferably 1 0 ^7-10 moles, more preferably 5 X 10- ⁷ is a ~5 X 1 (J- ⁴ mols. reaction rate improving effect as 10 ⁸ less than mole may become insufficient, leading to 10- ² mol is exceeded and cost.

The above three types of catalyst components (A) active hydrogen-containing nitrogen-containing heterocyclic compound, (B) metal compound and (C) nitrogen-containing basic organic compound are usually used in molar ratios. , (A) / (B) is ^{^{1 0 4 ~: I 0- 3}} , preferably 10 ³ to 10-', further preferred properly is ^{5 X 1 0 2 ~: 1} , 1 is (C) / (B) 0 ⁴ to 1 0 ^3, preferably 1 0 ³ - 10 ^1, still more preferably used in an amount of 10 ² to 5 X 10- ^1. The catalyst components (A), (B) and (C) are usually added to the reaction system at the same time as the dihydroxy compound and the carbonic acid diester are charged in order to carry out the transesterification reaction. Next, suitable reaction conditions for performing the S-exchange reaction in the method of the present invention will be described.

The reaction temperature of the transesterification is not particularly limited, but is usually in the range of 100 ° C to 330 ° C, preferably 160 ° C to 300 ° C, and more preferably 180 ° C gradually according to the progress of the reaction. It is desirable to increase the temperature to 300 ° C. If the reaction temperature is lower than 100, the progress of the transesterification reaction is slow, and if it is higher than 330 ° C, the polycarbonate may be thermally degraded, which is not preferable.

The pressure at the time of the transesterification is set according to the reaction temperature according to the pressure of the monomer used. This is not limited as long as the reaction is set to be performed efficiently. Usually, at the beginning of the reaction, the atmospheric pressure or the pressure is increased to 1 to 50 atm (760 to 38000 torr), and the pressure is reduced at the late stage of the reaction, and preferably 0.01 to Often I 00 torr. Further, the reaction time of the transesterification reaction may be carried out until a polycarbonate having a target molecular weight is obtained, and is usually about 0.2 to 10 hours.

The transesterification reaction is preferably performed in an atmosphere of an inert gas such as nitrogen or argon.If necessary, a branching agent, a terminal terminator, an antioxidant, etc. may be added, or an inert solvent may be used. May be.

As a branching agent, a polyfunctional compound having three or more functional groups in one molecule is used, and examples of such a polyfunctional compound include florodalcine, pyrogallol, 1, 1, 1— Tris (4-hydroxyphenyl) methane, 1,1,1-tris (4-hydroxyphenyl) ethane, 1,1,1-tris (4-hydroxyphenyl) propane, 1,1,1-tris (3 —Methyl-4—hydroxyphenyl) ethane, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) 1-2-heptene, 4,6-dimethyl-2,4,6-tris (4 -Hydroxyphenyl) Heptane, 2,6-Dimethyl 2,4,6-Tris (4-Hydroxyphenyl) Phenyl) _3-heptene, 1,35-tris (2-hydroxyphenyl) benzene, 1,3,5-tris (4-hydroxyphenyl) benzene, tris (4-hydroxyphenyl) -phenylmethane, 2,2 —Bis [4,4-bis (4-hydroxyphenyl) cyclohexyl] pro. 2,4-bis [α- (4-hydroxyphenyl) isopropyl] phenol, 2,6-bis (2'-hydroxy-5'-methylbenzyl) -14-methylphenol, 2- (4- human Dorokishifu Eniru) Single 2- (2, 4 dihydric Dorokishifueniru) flop ⁰ down, Do, Do ', a "- tris (4-arsenate Dorokishifuwe sulfonyl) one 1, 3, 5-triisopropylbenzene, alpha-methyl I α, a ', a' — tris (4-hydroxyphenyl) 1,1,4-diethylbenzene, hexakis [4- {a- (4-hydroxyphenyl) isopropyl) phenyl] — 0-terephthalic acid ester, Tetrakis (4-hydroxyphenyl) methane, tetrakis [4- {a- (4-hydroxyphenyl) isopropyl) phenoxy] methane, 1,4-bis [(4 ', 4 "—dihydroxytriphenyl) methyl] Ben 2,4-dihydroxybenzoic acid, trimellitic acid, trimesic acid, pyromellitic acid, cyanuric chloride, 3,3-bis (3-methyl-4-hydroxyphenyl) 1-2-oxo-1,2 —Dihydroindole, 3,3-bis (4-hydroxyaryl) oxyindole, 5-chloroisatin, 5,7-dichloroisatin, 5-promoisatin phloroglyside, and the like.

Examples of the terminal stopper include o-n-butylphenol, mn-butylphenol, pn-butylphenol, o-isobutylphenol, m-isobutylphenol, p-isobutylphenol, o-t-butylphenol, m — T—butylphenol, p—t-butylphenol, o—n—pentylphenol, m—n—pentylphenol, p—n—pentylphenol, o—n—hexylphenol, m— n-hexylphenol, p-n-hexylphenol, o-cyclohexylphenol, m-cyclohexylphenol, p-cyclohexylphenol, o-phenylphenol, m-phenylphenol, p- Phenol phenol, 0—n-noninolephenol, m—n—nonylphenol, p—n—nonylphenol, o—cumylphenol, m— Kumil Penol, p—Quirmil Enol, o-naphthylphenol, m-naphthylphenol, p-naphthylphenol, 2,6-di-t-butylphenol, 2,6-di-t-butylphenol, 2,4-di-t-butylphenol, 3,5-di-tert-butylphenol, 2,5-dicumylphenol, 3,5-dicumylphenol, 1-benzyl (4-hydroxybenzyl) benzene, dibenzyl-4- (4-hydroxybenzyl) Benzyl) Benzene and monovalent phenols such as chroman derivatives such as 2,2,4-trimethyl-41- (4-hydroxyphenyl) chroman and 2,4,4-trimethyl-4-1- (4-hydroxyphenyl) chroman Is mentioned.

Among such phenols, p-t-butylphenol, p-cumylphenol, p-phenylphenol and the like are not particularly limited in the present invention.

Further, a carbonic acid diester compound is sometimes used as another terminal stopper. Specific examples of such a terminal ester terminator of the carbonic acid diester compound include carboxy toxyl phenyl carbonate, methyl phenyl butyl X carbonyl carbonate, ethyl butyl phenyl carbonate and dibutyl diphenyl carbonate. Penyl carbonate, biphenyl phenyl carbonate, dibiphenyl carbonyl, cumyl phenyl carbonate, dicumyl phenyl carbonate, naphthyl phenyl carbonate, dinaphthyl phenyl carbonate, carboxypropenyl phenyl Carbonate, carboheptoxyphenyl phenyl carbonate, carboxy methoxy t-butyl phenyl phenyl carbonate, carbopropoxy phenylinolemethinolephenyl carbonate, chromanyl phenyl carbonate, dichromium luca -Bonnet and the like. Also C 7-3. —Alkyl-powered ponyloxybenzene, C ₇ _—3 . - fatty alcohols, Fuweniru (C - alkoxy) benzo er Bok, Fuweniru di (C _{1 2} - alkoxy) Benzoe bets, Fuweniru tri (C Medical _{1 2} - alkoxy) benzoate, Fuweniru _{(d-1 2} - alkoxy) sul Honeto And the like.

When the amount of the terminal terminator is in the range of 0.05 mol% to 10 mol% with respect to 1 mol of the dihydroxy compound, the hydroxyl terminal of the obtained polycarbonate is blocked. Therefore, it is preferable to obtain a polycarbonate having sufficiently excellent heat resistance and water resistance. The above-mentioned monohydric phenol / carbonic acid diester as a terminal terminator may be previously added to the reaction system in its entirety, or may be partially added to the reaction system in advance, and the remainder may be added as the reaction proceeds. You may. Further, in some cases, the whole amount may be added to the reaction system after the polycondensation reaction between the dihydroxy compound as a monomer raw material and the carbonic acid diester partially proceeds. When one of the monomer components is brought into contact with one of (A) an active hydrogen-containing nitrogen-containing heterocyclic compound and (B) a metal compound as a pretreatment step before the transesterification reaction, The terminating agent may be added in its entirety to the mixture used in the pretreatment step, or to the reaction system for the Seneole exchange reaction after the pretreatment step. Some may be added to the system, and the remainder may be added as the transesterification reaction proceeds. Further, in some cases, the whole amount may be added to the reaction system after the ester exchange reaction between the dihydroxy compound and the carbonic acid diester has progressed to some extent.

As antioxidants, tris (nonylphenyl) phosphite, trisphenyl phosphite, 2-ethylhexyldiphenyl phosphite, trimethyl phosphite, triethyl phosphite, tricresyl phosphite, triaryl Phosphorous antioxidants such as phosphites are preferably used.

Examples of the inert solvent usable in the present invention include aromatic compounds such as diphenyl ether, halogenated diphenyl ether, diphenyl sulfone, benzophenone, polyphenyl ether, dichlorobenzene and methylnaphthalene, and carbon dioxide monoxide. Gases such as dinitrogen and nitrogen, chlorofluorocarbons, alkanes such as ethane and propane, cyclohexane, tricyclo (5,2,10) —cycloalkanes such as decane, cyclooctane and cyclododecane, ethylene And various things such as argen such as propene or hexafluoride.

In addition, known additives such as a plasticizer, a pigment, a lubricant, a release agent, a stabilizer, and an inorganic filler can be compounded and used in the polycarbonate obtained by the present invention.

These polycarbonates are made of polyolefins, polystyrene, etc. It is possible to blend the mer, in particular OH group, COOH group, polyphenylene ethers having like end NH ₂ group, polyether nitrile, terminal-modified policy Rokisan compound, modified polypropylene, when used in combination with modified polystyrene It is effective.

Hereinafter, the present invention will be described more specifically with reference to Examples of the present invention and Comparative Examples thereof, but the present invention is not limited to these Examples.

Examples 1-4, Comparative Example 1

The compound marked with a mark in Table 1 was added to the sample tube, a stirrer chip was inserted, and the tube was sealed in a nitrogen environment. This ampule tube was placed in an oil bath maintained at 150 ° C, and stirred for 30 minutes (pretreatment step). Next, in order to carry out the transesterification reaction, the remaining compounds marked with a triangle were added, the tube was sealed under a nitrogen environment, and the reaction was carried out at 150 ° C for 1 hour (transesterification reaction). After completion of the reaction, the produced phenol was quantified by gas chromatography to determine the reaction rate. Table 1 shows the results.

BPA: bisphenol ノール, amount added = 0.3 g (0.0013 mol)

DP C: diphenyl carbonate, addition amount = 0.56 g (0.20026 mol)

2 -Hy P y: 2- hydroxycarboxylic pyridine, the addition amount - 2 x 10- ² moles Z moles BPA Mn (OA c) _2:? Acetate "^ cancer, amount = 2 x 10- ⁴ mol / mol BPA Example 5

The same operation as in Example 3 was performed except that magnesium acetate was used in the same ratio instead of manganese acetate. The conversion was 85%. Comparative Example 2

The same operation as in Example 5 was performed except that the transesterification reaction was performed directly without performing the pretreatment step of bringing diphenyl carbonate and magnesium acetate into contact with each other. The conversion was 42%. Examples 6 and 7, Comparative Examples 3 and 4

Pretreatment step: 內 Bisphenol A (228 g, 1.00 mol) and manganese acetate (0.0245 g, 0.0001 mol) were charged into a 1.4-liter Ni steel autoclave equipped with a stirrer. The displacement was performed 5 times, and the mixture was stirred at 180 rpm for 30 minutes (pretreatment step)

Transesterification reaction: Then, 225 g (1.05 mol) of diphenyl carbonate and 0.001 mol of the compound shown in Table 2 were added, the temperature was raised to 240 ° C, and vacuum was applied to ImmHg over 1 hour. Increased the degree. Next, the temperature was set to 270 ° C, the degree of vacuum was set to ImmHg, and the reaction was performed for 1 hour. Finally, a viscous, clear condensate remained in the autoclave.

The condensate obtained was dissolved in methylene chloride, and the viscosity average molecular weight was measured. Further, the obtained viscous and transparent condensate was pulverized, press-molded at 270 to form a sheet, and the hydrolysis resistance was measured. Table 2 shows the results. Comparative Example 5

Same as Example 6 except that the pre-treatment of bringing bisphenol A and manganese acetate into contact was not performed, and all the monomer components and the catalyst were added simultaneously to carry out the transesterification reaction. The same operation was performed. _C Table 2 shows the results in Table 2

1) 20 to measure the [] of in _{_{CH 2 C 1 2, [77}} ] = 1. 2 3 X 1 0- 5 Μν. · Calculated from ⁸³ .

2) The condition after exposing the sheet (thickness: 3 mm) to 121 steams for 48 hours was judged visually.

3) Since the condensates obtained in Comparative Examples 3 and 4 had a low molecular weight and no effect of accelerating the reaction, it was not evaluated for hydrolysis resistance.

4) No pretreatment step Example 8-: I5, Comparative example 6-9

In a 1.4-liter Ni steel autoclave (with a stirrer), 228 g (1.00 mol) of bisphenol A and 225 g (1.05 mol) of diphenyl carbonate were contained as shown in Table 3. A nitrogen basic organic compound, an active hydrogen-containing nitrogen-containing heterocyclic compound and a metal compound were charged, and nitrogen substitution was performed five times. The mixture was heated to 180 ° to melt the bisphenol A and diphenyl carbonate. Then, the temperature was set to 220, stirring was started at the same time, and a slight amount of nitrogen was passed, and the phenol formed began to evaporate. The reaction temperature was maintained at 220 ° C for 1 hour. Thereafter, the temperature was raised to 240 ° C and the degree of vacuum was gradually raised to 1 OmmHg, and the reaction was performed for 1 hour. Then, the temperature was set to 270 ° C, the degree of vacuum was set to ImmHg, and the mixture was reacted for 1 hour.

Finally, a viscous, clear condensate remained in the autoclave. This substance was dissolved in methylene chloride and the viscosity average molecular weight was measured. Further, the obtained condensate was pulverized and press-molded at 280 ° C. to obtain a 3 mm-thick sheet, which was used to measure hydrolysis resistance. The results are shown in Table 4.

Table 3 Catalyst (mol / molBPA) Catalyst (mol / molBPA), Catalyst (mol / molBPA)

Run

(C) Type weight (A) Type ft (B) Type weight Example 8 (CH3) ₄ NOH 1x10-5 2- human 'Rokishipirijin ^{1 10' 3 Mn (AcO)} 2 1 x 5 Example 9 (C) ₄ NOH _ixio-5 4- person 'Rokishipirijin ^{1 X 10' 3 Mn (AcO} ) 2 1 x 10-5 example _{10 (C¾) 4 NOH 1 X} 10- 5 2- arsenide Fa Kishiki / phosphorus lxlO- ³ Mn (AcO) ₂ l ir example _{_{11 (CH 3) 4 NOH 1}} X 5 2- person 'mouth Kishibirijin ^{1 10' 3 Mg (AcO)} 2 1 x it) - 5 example _{12 (C¾) 4 NBH4 ixio-} 5 2-!: Toloxypyridine 1 X 10 ³ Zn (AcO) ₂ 1 x 10 " ⁵ Example 13 (CHs) ₄ NBH4 IX ⁵ 2-Human 'roxypyridine lxlO ³ Co (AcO) ₂ 1 10 ⁵ Example _{_{_{14 (C 4 H e) 4}}} NBH4 1X10 '5 2- 1 bets' 0 Kishipirijin _{1 X 10-3 Mn (AcO) 2} l lo- 5

N, N—Dimethi

Example 15 ro 4-amido 1x10-5 2-human 'π xypyridine 1 X 10.3 Mn (AcO) ₂ lx 10-5 nopyridine

Comparative Example _{_{_{6 (C 4 H 9) 4}}} NBH4 lxlO '5 Comparative Example 7 2 - human' mouth Kishipirijin ^{1 X 10- 3 Mn (AcO)} 2 1 x 10- 5 Comparative Example _{8 Mn (AcO) 2 1 x} 10 5 Comparative example 9 LiOH 1 x 10- ⁵ Table 4

[?;] 1) 20, in CH ₂ C 1 ₂ was measured and calculated from ^{[Ri] = 1. 23 x 10- 5 X} Μν ° · 83.

3) Since the condensates obtained in Comparative Examples 6 to 8 had a low molecular weight and apparently had no effect of promoting the reaction, the hydrolysis resistance was not evaluated. Industrial applications

According to the present invention, when a polycarbonate is produced by a transesterification method, the amount of a conventionally used transesterification catalyst can be reduced to provide a high quality polycarbonate. Nets can be manufactured with high productivity.

Claims

The scope of the claims

1. Using (A) an active hydrogen-containing nitrogen-containing heterocyclic compound and (B) a metal compound as catalysts, and prior to producing polycarbonate by the esterification exchange reaction between a dihydroxy compound and a diester carbonate as monomer raw materials, Production of a polycarbonate characterized by mixing and contacting the dihydroxy compound or the carbonic acid diester with the active hydrogen-containing nitrogen-containing heterocyclic compound and / or the metal compound.

2. The dihydroxy compound and the metal compound are mixed and brought into contact in advance, and then the ester exchange reaction is performed by adding the carbonic acid diester and the active hydrogen-containing nitrogen-containing ring compound to the mixture. The process for producing the polycarbonate according to the above.

3.1 ^0-7 to 1 mol of active hydrogen-containing nitrogen-containing heterocyclic compounds to the dihydroxy compounds 1 mol of the metal compound the dihydric Dorokishi Compound 1 mol 1 0 ⁸ -

1 0 ² mole used, the preparation of polycarbonate Bok according to claim 1, wherein the molar ratio of the active hydrogen-containing nitrogen-containing heterocyclic compound wherein the metal compound is 1 0 ⁴ to 1 0 ^3.

4. The active hydrogen-containing nitrogen-containing heterocyclic compound is selected from the group consisting of a hydroxy-substituted nitrogen-containing heterocyclic compound, a mercapto-substituted nitrogen-containing heterocyclic compound and an amino-substituted nitrogen-containing heterocyclic compound, and the metal compound is 2. The method for producing a polycarbonate according to claim 1, which is a compound of a metal selected from the group consisting of Ca, Mg, Mn, Zn, Ti, and Co.

5. The nitrogen-containing heterocyclic compound containing active hydrogen is selected from the group consisting of hydroxypyridine, mercaptopyridine, aminopyridine, hydroxyquinoline, mercaptoquinoline and aminoquinoline, and the metal compound is Ca, oxidized calcium. , Calcium hydroxide, calcium amide, calcium alcohol, calcium Phenolate, calcium acetate, Mg, magnesium oxide, magnesium hydroxide, magnesium amide, magnesium alcoholate, magnesium phenolate, magnesium acetate, manganese acetate, zinc oxide, zinc acetate, organic titanium compound 5. The method for producing a polycarbonate according to claim 4, which is selected from the group consisting of a substance and cobalt acetate.

6. The active hydrogen-containing nitrogen-containing heterocyclic compound is 2-hydroxypyridine, 4-hydroxypyridine or 2-hydroxyquinoline, and the metal compound is manganese acetate, magnesium acetate, zinc acetate or cobalt acetate. The method for producing a polycarbonate according to range 5.

7. The dihydroxy compound is bisphenol A, the carbonic diester is diphenyl carbonate, the metal compound is manganese acetate or magnesium acetate, and the active hydrogen-containing nitrogen-containing heterocyclic compound is 7. The method for producing a polycarbonate according to claim 6, which is hydroxypyridine or 4-hydroxypyridine.

8. In producing polycarbonate by transesterification reaction from a dihydroxy compound and a carbonic acid diester, (A) an active hydrogen-containing nitrogen-containing heterocyclic compound,

A process for producing a polycarbonate, characterized by using (B) a metal compound and (C) a nitrogen-containing basic organic compound as a catalyst.

9. The active nitrogen-containing nitrogen-containing heterocyclic compound is added to 1 mole of the dihydroxy compound.

1 0 ^8-1 moles, 1 0 ^8-1 0 ² mol the metal compound relative to the dihydroxy compound to 1 mole, the nitrogen-containing basic organic compound to the dihydric Dorokishi Compound 1 mol 1 0 ⁸ using ~ 1 0 ² mole, the molar ratio of the active hydrogen-containing nitrogen-containing heterocyclic compound Z the metal compound is 1 0 ⁴ to 1 0 ³ molar ratio of the nitrogen-containing basic organic compound Monono該metal compound is 1 0 ⁴ preparation of polycarbonate according to claim 8, wherein a and 1 0 ^3.

10.The active hydrogen-containing nitrogen-containing heterocyclic compound is selected from the group consisting of a hydroxy-substituted nitrogen-containing heterocyclic compound, a mercapto-substituted nitrogen-containing heterocyclic compound and an amino-substituted nitrogen-containing heterocyclic compound; The metal compound is a metal compound selected from the group consisting of Ca, Mg, Mn, Zn, Ti, and Co; and the nitrogen-containing basic organic compound is an aliphatic tertiary amine compound; Aromatic tertiary amine compounds, N, N-dimethyl-14-aminopyridine, N, N-getyl-14-aminopyridine, 4-pyrrolidinopyridine, 2-methoxypyridine, 4-methoxypyridine, 2-dimethylamido Neumidazole, 2-Methoxyimidazole, Imidazole, 2-Methylimidazole, 4-Methylimidazole, Diazabicyclooctane, Tetraalkylammonium hydroxide, 9. The process for producing a polycarbonate according to claim 8, which is selected from the group consisting of tetraarylammonium hydroxide, tetra (alkylaryl) ammonium hydroxide and a basic salt of boric acid.

11. The active hydrogen-containing nitrogen-containing heterocyclic compound is selected from the group consisting of hydroxypyridine, mercaptopyridine, aminoviridine, hydroxyquinoline, mercaptoquinoline and aminoquinoline, and the metal compound is Ca, Calcium oxide, calcium hydroxide, calcium amide, calcium alcoholate, calcium phenolate, calcium acetate, Mg, magnesium oxide, 7_ magnesium oxide, magnesium amide, magnesium alcoholate, magnesium phenolate, magnesium acetate, acetic acid Selected from the group consisting of manganese, zinc oxide, zinc acetate, organic titanium compounds and cobalt acetate, wherein the nitrogen-containing basic organic compound is trihexylamine, tetramethylammonium hydroxide, tetra 10. The process for producing a polycarbonate according to claim 10, which is butyl ammonium hydroxide, tetramethyl ammonium borohydride, tetrabutyl ammonium borohydride, or N, N-dimethyl-4-aminopyridine. .

1 2. The active hydrogen-containing nitrogen-containing heterocyclic compound is 2-hydroxypyridine, 4-hydroxypyridine or 4-hydroxyquinoline, and the metal compound is Cancer, magnesium acetate, zinc acetate or cobalt acetate, wherein the nitrogen-containing basic organic conjugate is tetramethylammonium hydroxide, tetramethylammonium polohydride, tetrabutylammoniumborohydride Or the method for producing a polycarbonate according to claim 11, which is N, N-dimethyl-4-aminopyridine.

13. The process for producing a polycarbonate according to claim 12, wherein said dihydroxy conjugate is bisphenol A, and said carbonic acid diester is diphenyl carbonate.