JPH1045896A - Production of polycarbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the efficient production of a polycarbonate polymer which is excellent in resistance to heat and hydrolysis and in color tone and is useful as an optical material by carrying out the ester-interchanging reaction by using specifically combined catalysts at high reaction rate. SOLUTION: When a dihydroxy compound (for example, bis-phenol A) and carbonic diester (for example, diphenyl carbonate) are subjected to the transesterification reaction, (A) a nitrogen-containing base, for example, an aliphatic or aromatic tertiary amine, a nitrogen-containing heterocyclic compound or a quaternary ammonium salt and (B) a quaternary phosphonium salt of formula I [R<2> is organic group where at least one is an aryl; X<2> is a halogen, OH, the formula: BR4 (R is H, a hydrocarbon group)], formula II (Y<2> is CO3 ), formula III (R' is a hydrocarbon group, an alkoxy, OH or the like; (n) is 1-3) are combined and used as a catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polycarbonate, and more particularly, to a transesterification reaction,
For example, when producing a polycarbonate by a transesterification reaction using a dihydroxy compound and a carbonic acid diester, by using a combination of a nitrogen-containing organic basic compound and a specific quaternary phosphonium salt as a polymerization catalyst, the catalytic activity is sufficient. The present invention relates to a method capable of efficiently producing a high-quality polycarbonate, which is capable of improving the reaction rate, and capable of removing the catalyst by thermal decomposition at the final stage of the reaction.

[0002]

2. Description of the Related Art Polycarbonate is an engineering plastic having excellent transparency, heat resistance and impact resistance, and is currently widely used in electric / electronic fields, automobile fields, optical parts fields and other industrial fields. In general, as a method for producing a polycarbonate, a method of directly reacting an aromatic dihydroxy compound with phosgene (interfacial polycondensation method) or a method of transesterifying an aromatic dihydroxy compound and a diester carbonate in a molten state (melt polymerization method) )It has been known. In this polycarbonate production method, the interfacial polycondensation method requires that toxic phosgene must be used, that the production equipment is corroded by by-product chlorine-containing compounds such as hydrogen chloride and sodium chloride, and that chloride mixed in the resin is used. There are various problems such as difficulty in separating impurities such as sodium which adversely affect the physical properties of the polymer. On the other hand, the transesterification method (melt polymerization method) has the advantage that polycarbonate can be produced at lower cost than the interfacial polycondensation method,
Usually, the reaction is carried out at a high temperature of 280 to 310 ° C. for a long time, so there is a great disadvantage that the obtained polycarbonate is inevitably colored, and a basic catalyst is often used. There was also a problem that hydrolysis was poor.

In this transesterification method (melt polymerization method), in order to solve the problem of coloring of polycarbonate, for example, a method using a specific catalyst (Japanese Patent Publication No. Sho.
JP-A-1-39972, JP-A-63-223036 and the like, and a method of adding an antioxidant at the latter stage of the reaction (JP-A-61-151236, JP-A-62-15871).
No. 9) and a method using a twin-screw vent-type kneading extruder (Japanese Patent Application Laid-Open No. 61-62522) or a horizontal stirring polymerization tank (Japanese Patent Application Laid-Open No. 2-153925) in the late stage of the reaction. ing. However, even in these methods, regarding the coloring problem of polycarbonate,
Not yet fully resolved. On the other hand, as a method for improving the hydrolysis resistance of 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. Although techniques for neutralizing an excess acid with an epoxy compound have been disclosed (JP-A-4-175368, etc.), these techniques cannot sufficiently improve the hydrolysis resistance of polycarbonate. It is a fact.
Further, as a method using a specific catalyst, it has recently been disclosed to use a tetraalkylphosphonium hydroxide or a tetraarylphosphonium hydroxide (JP-A-6-256497). There is no essential difference between the two, and the hydrolysis resistance is not sufficient.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the drawbacks of such a conventional method for producing a polycarbonate by transesterification, can increase the reaction rate, and has heat resistance and hydrolysis resistance. It is an object of the present invention to provide a method capable of efficiently producing a high-quality polycarbonate excellent in color tone and good in color tone.

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that when a transesterification reaction is carried out using a dihydroxy compound and a diester carbonate, a nitrogen-containing catalyst is used as a catalyst. By using a combination of an organic basic compound and a quaternary phosphonium salt containing an aryl group, the polymer has sufficient catalytic activity from the beginning to the end of the transesterification reaction, and can be thermally decomposed at the final stage of the reaction. It has been found that the object can be achieved without deteriorating the quality. The present invention has been completed based on such findings. That is, the present invention is characterized in that in producing a polycarbonate by a transesterification reaction, a combination of (a) a nitrogen-containing organic basic compound and (b) a quaternary phosphonium salt containing an aryl group is used as a polymerization catalyst. The present invention provides a method for producing polycarbonate.

[0006]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a polycarbonate is produced by a transesterification reaction. There are no particular restrictions on the raw materials used in this transesterification method, and various materials used for production by a normal transesterification method are used. For example, in the transesterification reaction, a dihydroxy compound is used as the component (A), a diester carbonate is used as the component (B), a diester of a dihydroxy compound is used as the component (A), a diester carbonate is used as the component (B), and a dihydroxy compound is used as the component (A). Examples of the carbonate and the component (B) include diester carbonate, dicarbonate of a dihydroxy compound (self-condensation), and monocarbonate of a dihydroxy compound (self-esterification). Among these,
A dihydroxy compound is preferably used as the component (A) and a diester carbonate is used as the component (B).

The component (A) dihydroxy compound preferably used in the transesterification reaction includes, for example, an aromatic dihydroxy compound and an aliphatic dihydroxy compound, and is at least one compound selected from these. The aromatic dihydroxy compound used as one of the components (A) has the general formula (XI)

[0008]

Embedded image

Compounds represented by the following formulas can be mentioned.
In the general formula (XI), R ⁴ and R ⁵ are each a halogen atom of fluorine, chlorine, bromine, or iodine or an alkyl group having 1 to 20 carbon atoms, for example, a methyl group, an ethyl group, and n
-Propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, cyclohexyl, hebutyl, octyl and the like. R ⁴ and R ⁵ may be the same or different. The plurality of R ⁴ if R ⁴ is more may be the same or different, a plurality of R ⁵ if R ⁵ there are a plurality may be the same or different. m
And n are each an integer of 0 to 4. And Z is a single bond, an alkylene group having 1 to 20 carbon atoms, and a carbon atom having 2 to 2 carbon atoms.
0 alkylidene group, cycloalkylene group having 5 to 20 carbon atoms, cycloalkylidene group having 5 to 20 carbon atoms, or-
S—, —SO—, —SO ₂ —, —O—, —CO— bond or formula (XII), (XII ′)

[0010]

Embedded image

[0011] The bond shown by the following is shown. Examples of the alkylene group having 1 to 20 carbon atoms and the alkylidene group having 2 to 20 carbon atoms include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an ethylidene group, and an isopropylidene group. 5 to 2 carbon atoms
Examples of the cycloalkylene group having 0 and the cycloalkylidene group having 5 to 20 carbon atoms include a cyclopentylene group, a cyclohexylene group, a cyclopentylidene group, and a cyclohexylidene group.

Examples of the aromatic dihydroxy compound represented by the general formula (XI) include bis (4-hydroxyphenyl) methane; bis (3-methyl-4-hydroxyphenyl) methane; and bis (3-chloro-4). -Hydroxyphenyl) methane; bis (3,5-dibromo-4-hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl) ethane; 1,1-bis (2-t-butyl-4)
-Hydroxy-3-methylphenyl) ethane; 1,1-
Bis (2-t-butyl-4-hydroxy-3-methylphenyl) ethane; 1-phenyl-1,1-bis (3-fluoro-4-hydroxy-3-methylphenyl) ethane; 2,2-bis ( 4-hydroxyphenyl) propane (commonly known as bisphenol A); 2,2-bis (3-methyl-4-hydroxyphenyl) propane; 2,2-bis (2-methyl-4-hydroxyphenyl) propane;
2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane; 1,1-bis (2-t-butyl-4-
(Hydroxy-5-methylphenyl) propane; 2,2-
Bis (3-chloro-4-hydroxyphenyl) propane; 2,2-bis (3-fluoro-4-hydroxyphenyl) propane; 2,2-bis (3-bromo-4-hydroxyphenyl) propane; 2,2 -Bis (3,5-difluoro-4-hydroxyphenyl) propane; 2,2
-Bis (3,5-dichloro-4-hydroxyphenyl)
Propane; 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane; 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-bis (4-hydroxy-3,5-dibromophenyl) propane; 2,2-bis (3-bromo-4-hydroxy-5-chlorophenyl) propane; 2,2-bis (3-phenyl-4-hydroxy Phenyl) propane;
2,2-bis (4-hydroxyphenyl) butane; 2,
2-bis (3-methyl-4-hydroxyphenyl) butane; 1,1-bis (2-butyl-4-hydroxy-5-
1,1-bis (2-t-butyl-4-hydroxy-5-methylphenyl) butane;
1,1-bis (2-t-butyl-4-hydroxy-5-
Methylphenyl) isobutane; 1,1-bis (2-t-
Amyl-4-hydroxy-5-methylphenyl) butane; 2,2-bis (3,5-dichloro-4-hydroxyphenyl) butane; 2,2-bis (3,5-dibromo-
4-hydroxyphenyl) butane; 4,4-bis (4-
Hydroxyphenyl) heptane; 1,1-bis (2-t
-Butyl-4-hydroxy-5-methylphenyl) heptane; 2,2-bis (4-hydroxyphenyl) octane; bis (hydroxyaryl) alkanes such as 1,1- (4-hydroxyphenyl) ethane; 1-bis (4-hydroxyphenyl) cyclopentane; 1,1-
Bis (4-hydroxyphenyl) cyclohexane; 1,
1-bis (3-methyl-4-hydroxyphenyl) cyclohexane; 1,1-bis (3-cyclohexyl-4-)
1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane; 1,1-bis (4-hydroxyphenyl) -3,
Bis (hydroxyaryl) cycloalkanes such as 5,5-trimethylcyclohexane; bis (4-hydroxyphenyl) ether; bis (4, -hydroxy-3-
Bis (hydroxyaryl) ethers such as methylphenyl) ether; bis (4-hydroxyphenyl) sulfide; bis (hydroxyaryl) sulfides such as bis (3-methyl-4-hydroxyphenyl) sulfide; bis (4-hydroxy Bis (3-methyl-4-hydroxyphenyl) sulfoxide; bis (hydroxyaryl) sulfoxides such as bis (3-phenyl-4-hydroxyphenyl) sulfoxide; bis (4hydroxyphenyl) sulfone; bis (3 -Methyl-4-hydroxyphenyl) sulfone; bis (3-phenyl-4-hydroxyphenyl)
Bis (hydroxyaryl) sulfones such as sulfone, 4,4′-dihydroxybiphenyl; 4,4′-dihydroxy-2,2′-dimethylbiphenyl; 4,4 ′
-Dihydroxy-3,3'-dimethylbiphenyl; 4,
Dihydroxybiphenyls such as 4'-dihydroxy-3,3'-dicyclohexylbiphenyl;3,3'-difluoro-4,4'-dihydroxybiphenyl;

Examples of the aromatic dihydroxy compound other than the general formula (XI) include dihydroxybenzenes, halogen- and alkyl-substituted dihydroxybenzenes.
For example, resorcin, 3-methyl resorcin, 3-ethyl resorcin, 3-propyl resorcin, 3-butyl resorcin, 3-t-butyl resorcin, 3-phenyl resorcin, 3-cumyl resorcin; 2,3,4,6- Tetrafluororesorcin; 2,3,4,6-tetrabromoresorcin; catechol, hydroquinone, 3-methylhydroquinone, 3-ethylhydroquinone, 3-propylhydroquinone, 3-butylhydroquinone, 3
-T-butylhydroquinone, 3-phenylhydroquinone, 3-cumylhydroquinone; 2,5-dichlorohydroquinone; 2,3,5,6-tetramethylhydroquinone; 2,3,4,6-tetra-t-butylhydroquinone 2,3,5,6-tetrafluorohydroquinone; and 2,3,5,6-tetrabromohydroquinone.

There are various aliphatic dihydroxy compounds used as one of the components (A). For example, butane-1,4-diol; 2,2-dimethylpropane-1,3-diol; hexane-1,6-diol
Diols; 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;
Ethoxylated or propoxylated products of 2-bis- (4-hydroxycyclohexyl) -propane and dihydric alcohols or phenols, such as bis-oxyethyl-bisphenol A; bis-oxyethyl-tetrachlorobisphenol A or bis-oxyethyl-tetrachloro Hydroquinone and the like.

In a preferred production method of the present invention,
As the dihydroxy compound of the component (A), one or more of the above compounds are appropriately selected and used, and among these, bisphenol A which is an aromatic dihydroxy compound is preferably used. On the other hand, in the present invention,
There are various types of carbonate diester used as the component (B). For example, it is at least one compound selected from diaryl carbonate compounds, dialkyl carbonate compounds and alkylaryl carbonate compounds. The diaryl carbonate compound used as one of the components (B) has the general formula (XIII)

[0016]

Embedded image

(Wherein, Ar ¹ and Ar ² each represent an aryl group, which may be the same or different from each other), or a compound represented by the general formula (XIV)

[0018]

Embedded image

(In the formula, Ar ³ and Ar ⁴ each represent an aryl group, which may be the same or different, and D ¹ represents a residue obtained by removing two hydroxyl groups from the aromatic dihydroxy compound. ). The dialkyl carbonate compound has the general formula (XV)

[0020]

Embedded image

(Wherein R ⁶ and R ⁷ each have 1 carbon atom)
Represents an alkyl group having from 20 to 20 or a cycloalkyl group having from 4 to 20 carbon atoms, which may be the same or different. Or a compound represented by the general formula (XVI)

[0022]

Embedded image

(Wherein R ⁸ and R ⁹ each have 1 carbon atom)
Represents an alkyl group having from 20 to 20 or a cycloalkyl group having from 4 to 20 carbon atoms, which may be the same or different, and D ² represents a residue obtained by removing two hydroxyl groups from the aromatic dihydroxy compound. ).
The alkylaryl carbonate compound has the general formula (XVI
I)

[0024]

Embedded image

(Wherein, Ar ⁵ represents an aryl group, R ¹⁰ represents an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 4 to 20 carbon atoms), or a compound represented by the general formula (XV
III)

[0026]

Embedded image

(Wherein, Ar ⁶ is an aryl group, R ¹¹ is an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 4 to 20 carbon atoms, and D ³ is a group obtained by removing two hydroxyl groups from the aromatic dihydroxy compound. The compound is a compound represented by the following formula: Here, as the diaryl carbonate compound, for example,
Diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl)
Carbonate, bisphenol A bisphenyl carbonate and the like. Examples of the dialkyl carbonate compound include diethyl carbonate, dimethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, and bisphenol A bismethyl carbonate.

Examples of the alkylaryl carbonate compound include, for example, methyl phenyl carbonate, ethyl phenyl carbonate, butyl phenyl carbonate, cyclohexyl phenyl carbonate, bisphenol A
Methyl phenyl carbonate and the like can be mentioned. In the present invention, one or more of the above compounds are appropriately selected and used as the diester carbonate (B), and among these, diphenyl carbonate is preferably used.

Next, as raw materials other than the dihydroxy compound and the carbonic acid diester used in the present invention,
These include: That is, examples of diesters of dihydroxy compounds include diacetate of bisphenol A, dipropionate of bisphenol A, dibutylate of bisphenol A, and dibenzoate of bisphenol A. Examples of the dicarbonate of the dihydroxy compound include bismethyl carbonate of bisphenol A, bisethyl carbonate of bisphenol A, and bisphenyl carbonate of bisphenol A. Examples of monocarbonates of the dihydroxy compound include bisphenol A monomethyl carbonate, bisphenol A monoethyl carbonate, bisphenol A monopropyl carbonate, and bisphenol A monophenyl carbonate.

In the production method of the present invention, a terminal terminator can be used if necessary. Examples of the terminal stopper include on-butylphenol; m
-N-butylphenol; pn-butylphenol;
o-isobutylphenol; m-isobutylphenol; p-isobutylphenol; ot-butylphenol; mt-butylphenol; pt-butylphenol; on-pentylphenol; mn-pentylphenol; -Pentylphenol; on-
Hexylphenol; mn-hexylphenol; p
-N-hexylphenol; o-cyclohexylphenol; m-cyclohexylphenol; p-cyclohexylphenol; o-phenylphenol; m-phenylphenol; p-phenylphenol; on-nonylphenol; mn-nonylphenol; n-nonylphenol; o-cumylphenol; m-cumylphenol; p-cumylphenol; o-naphthylphenol; m-naphthylphenol; p-naphthylphenol; 2,6-di-t-butylphenol; -Ji-
t-butylphenol; 2,4-di-t-butylphenol; 3,5-di-t-butylphenol; 2,5-dicumylphenol; 3,5-dicumylphenol;

[0031]

Embedded image Or a compound represented by the formula

[0032]

Embedded image

Monovalent phenols such as chroman derivatives represented by Among such phenols,
Although not particularly limited in the present invention, pt-butylphenol, p-cumylphenol, p-phenylphenol and the like are preferable. Also, the formula

[0034]

Embedded image

Compounds represented by the following formulas can also be used. Furthermore, in the present invention, if necessary, phloroglucin; trimellitic acid; 1,1,1-tris (4-hydroxyphenyl) ethane; 1- [α-methyl-α- (4 ′)
-Hydroxyphenyl) ethyl] -4- [α ', α'-
Bis (4 "-hydroxyphenyl) ethyl] benzene;
α, α ', α "-tris (4-hydroxyphenyl)-
1,3,5-triisopropylbenzene; isatin bis (o-cresol) and the like can also be used as a branching agent.

In the production method of the present invention, a combination of (a) a nitrogen-containing organic basic compound and (b) a quaternary phosphonium salt containing an aryl group is used as a polymerization catalyst during the transesterification reaction. is necessary. The nitrogen-containing organic basic compound as the component (a) is not particularly limited.
There are various types. For example, trimethylamine, triethylamine, tripropylamine, tributylamine,
Aliphatic tertiary amine compounds such as tripentylamine, trihexylamine and dimethylbenzylamine; aromatic tertiary amine compounds such as triphenylamine; N, N
-Dimethyl-4-aminopyridine, 4-diethylaminopyridine, 4-pyrrolidinopyridine, 4-aminopyridine, 2-aminopyridine, 2-hydroxypyridine, 4
-Hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, imidazole, 2-methylimidazole, 4-methylimidazole, 2-dimethylaminoimidazole, 2-methoxyimidazole, 2-mercaptoimidazole, aminoquinoline, diazabicyclooctane ( DABCO) and the like.

Furthermore, the general formula _{^{(I) (NR 1 4)}} + (X 1) - ··· (I) or the general formula _{^{(II) (NR 1 4)}} + 2 (Y 1) 2- ··· (II) or the general formula (III) [(NR ¹ ₄₎ ⁺ O ^-] _n -P (= O) and the like quaternary ammonium salts represented by _{R '3-n ··· (III} ) it can.
In the above general formula (I), (II) or (III), R
¹ is an organic group such as a methyl group, an ethyl group, a propyl group,
Alkyl groups such as butyl group, pentyl group, hexyl group, octyl group, cyclohexyl group, cycloalkyl group, aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, biphenyl group, and arylalkyl groups such as benzyl group Is shown. The four R ^{1 's} may be the same or different, and two R ^{1' s} may combine to form a ring structure. In the general formula (I), X ¹
Represents a halogen atom, a hydroxyl group, an alkyloxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, HCO ₃ or BR ₄ , and in the general formula (II), Y ¹ represents CO ₃ . . Here, R represents a hydrogen atom or a hydrocarbon group such as an alkyl group or an aryl group, and the four Rs may be the same or different. In the general formula (III), R ′ represents a hydrocarbon group, an alkyloxy group, an aryloxy group or a hydroxyl group, R ′ may be the same or different, and n is an integer of 1 to 3.

As such a quaternary ammonium salt,
For example, ammonium hydroxides having an alkyl group, an aryl group, an araryl group and the like, such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, tetramethylammonium borohydride, tetrabutylammonium Examples include basic salts such as borohydride, tetrabutylammonium tetraphenylborate, and tetramethylammonium tetraphenylborate. Further, it may be a divalent anion as represented by the general formula (II), and examples thereof include bis (tetramethylammonium) carbonate. Alternatively, phosphates such as those represented by the general formula (III) may be used, and examples thereof include tetramethylammonium phosphate, tetramethylammonium phenylphosphate, and tetramethylammonium diphenylphosphate. Among these nitrogen-containing organic basic compounds, quaternary ammonium salts represented by the above general formula (I) are preferred because of their high catalytic activity, easy thermal decomposition, and low persistence in the polymer. Typically, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetramethylammonium borohydride,
Tetrabutylammonium borohydride is preferred, and tetramethylammonium hydroxide is particularly preferred. The nitrogen-containing organic basic compound as the component (a) may be used alone or in combination of two or more.

On the other hand, as the quaternary phosphonium salt of component (b), the general formula _{^{(IV) (PR 2 4)}} + (X 2) - ··· (IV) or the general formula (V) (PR ² _{4 ^{) + 2 (Y 2) 2-}} ··· (V) or general formula (VI) [(PR ² ₄₎ ⁺ O ^-] _{n -P (= O) R '} 3-n ··· (VI) The compound represented by these is mentioned. The above general formula (IV),
In (V) or (VI), R ² represents an organic group,
Examples of the organic group include the same as those exemplified in the description of R ¹ in the above general formula (I), but it is necessary that at least one of the four R ² is an aryl group. . The four R ^{2 s} may be the same or different, and two R ^2s may combine to form a ring structure. In the general formula (IV), X ²
Represents a halogen atom, a hydroxyl group, an alkyloxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, HCO ₃ or BR ₄ . here,
R represents a hydrogen atom or a hydrocarbon group such as an alkyl group or an aryl group, and the four Rs may be the same or different. In the general formula (V), Y ² represents CO ₃ . In the general formula (VI), R 'represents a hydrocarbon group, an alkyloxy group, an aryloxy group or a hydroxyl group, and R's may be the same or different, and n
Represents an integer of 1 to 3.

Such quaternary phosphonium salts include:
For example, tetraarylphosphonium hydroxides such as tetraphenylphosphonium hydroxide, tetranaphthylphosphonium hydroxide, tetra (chlorophenyl) phosphonium hydroxide, tetra (biphenyl) phosphonium hydroxide, tetratolylphosphonium hydroxide, methyltriphenylphosphonium hydroxide, Ethyltriphenylphosphonium hydroxide, propyltriphenylphosphonium hydroxide,
Butyltriphenylphosphonium hydroxide, amyltriphenylphosphonium hydroxide, heptyltriphenylphosphonium hydroxide, hexyltriphenylphosphonium hydroxide, octyltriphenylphosphonium hydroxide, tetradecyltriphenylphosphonium hydroxide, benzyltriphenylphosphonium hydroxide, Ethoxybenzyltriphenylphosphonium hydroxide, methoxymethyltriphenylphosphonium hydroxide, acetoxymethyltriphenylphosphonium hydroxide, phenacyltriphenylphosphonium hydroxide, chloromethyltriphenylphosphonium hydroxide, bromomethyltriphenylphosphonium hydroxide, biphenyltri Phenylphosphonium arsenic Monooxides such as loxide, naphthyltriphenylphosphonium hydroxide, chlorophenyltriphenylphosphonium hydroxide, phenoxyphenyltriphenylphosphonium hydroxide, methoxyphenyltriphenylphosphonium hydroxide, acetoxyphenyltriphenylphosphonium hydroxide, and naphthylphenyltriphenylphosphonium hydroxide (Aryl or alkyl) triarylphosphonium hydroxides, phenyltrimethylphosphonium hydroxide, biphenyltrimethylphosphonium hydroxide, phenyltrihexylphosphonium hydroxide, monoaryltrialkylphosphonium hydroxides such as biphenyltrihexylphosphonium hydroxide, dimethyldiphenyl Hos Di (aryl or alkyl) diarylphosphonium hydroxides such as sodium hydroxide, diethyldiphenylphosphonium hydroxide, di (naphthyl) diphenylphosphonium hydroxide, di (biphenyl) diphenylphosphonium hydroxide, and further tetraphenylphosphonium tetraphenylborate; Tetranaphthylphosphonium tetraphenylborate, tetra (chlorophenyl)
Tetraaryl phosphonium tetraphenyl borates such as phosphonium tetraphenyl borate, tetra (biphenyl) phosphonium tetraphenyl borate, tetratolyl phosphonium tetraphenyl borate, methyl triphenyl phosphonium tetraphenyl borate,
Ethyl triphenyl phosphonium tetraphenyl borate, propyl triphenyl phosphonium tetraphenyl borate, butyl triphenyl phosphonium tetraphenyl borate, octyl triphenyl phosphonium tetraphenyl borate, tetradecyl triphenyl phosphonium tetraphenyl borate, benzyl triphenyl phosphonium tetraphenyl borate, ethoxy Benzyltriphenylphosphonium tetraphenylborate,
Methoxymethyl triphenyl phosphonium tetraphenyl borate, acetoxymethyl triphenyl phosphonium tetraphenyl borate, phenacyl triphenyl phosphonium tetraphenyl borate, chloromethyl triphenyl phosphonium tetraphenyl borate, bromomethyl triphenyl phosphonium tetraphenyl borate, biphenyl triphenyl phosphonium tetra Phenyl borate, naphthyltriphenylphosphonium tetraphenylborate, chlorophenyltriphenylphosphonium tetraphenylborate, phenoxyphenyltriphenylphosphonium tetraphenylborate, acetoxyphenyltriphenylphosphonium tetraphenylborate, naphthylphenyltriphenylphosphonium tetraphenyl (Aryl or alkyl) triphenylphosphonium tetraphenylborate such as phenyl, phenyltrimethylphosphonium tetraphenylborate, biphenyltrimethylphosphonium tetraphenylborate, methyltrihexylphosphonium tetraphenylborate, ethyltrihexylphosphonium tetraphenylborate, octyltrihexyl Monoaryl trialkyl phosphonium tetraphenyl borates such as phosphonium tetraphenyl borate, stearyl trihexyl phosphonium tetraphenyl borate, phenyl trihexyl phosphonium tetraphenyl borate, biphenyl trihexyl phosphonium tetraphenyl borate, dimethyl diphenyl phosphonium tetraphenyl borate, diethyl Tetraphenylborate, di (naphthyl) diphenyl phosphonium tetraphenylborate, di (biphenyl) di diphenyl phosphonium tetraphenylborate (aryl or alkyl) diaryl phosphonium tetraphenyl borates and the like. In addition to the above compounds, allyltriphenylphosphonium hydroxide, sinamyltriphenylphosphonium hydroxide and the like can also be mentioned.

As the counter anion, instead of the above hydroxides and tetraphenyl borates, an aryloxy group such as phenoxide, an alkyloxy group such as methoxide and ethoxide, an alkylcarbonyloxy group such as acetate, and an aryl group such as benzoate are used. The above quaternary phosphonium salts using a halogen atom such as a carbonyloxy group, chloride and bromide are mentioned.
Further, in addition to the compound represented by the general formula (IV), those having a divalent counter anion represented by the general formula (V), for example, bis (tetraphenylphosphonium) carbonate, bis (biphenyltriphenyl) Phosphonium)
Quaternary phosphonium salts such as carbonate and bis (naphthyltriphenylphosphonium) carbonate, and further, for example, bis-tetraphenylphosphonium salt of 2,2-bis (4-hydroxyphenyl) propane, ethylenebis (triphenylphosphonium) dibromide, Trimethylene bis (triphenylphosphonium) -bis (tetraphenyl borate) and the like can also be mentioned.

Further, phosphates represented by the general formula (VI), for example, tetraphenylphosphonium phosphate, tetraphenylphosphonium phenylphosphate, tetraphenylphosphonium diphenylphosphate and the like can be mentioned. More preferably, in the production method of the present invention, a nitrogen-containing organic basic catalyst and a quaternary phosphonium represented by the following general formula (VIII), (IX) or (X) are used as a polymerization catalyst during the transesterification reaction. It is desirable to use a combination of compounds. Here, the general formula (VIII) is

Embedded image Wherein R ³ represents an organic group, which may be the same or different, and X ³ represents a halogen atom, a hydroxyl group, an alkyloxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, HCO ₃ Or BR
₄ (R represents a hydrogen atom or a hydrocarbon group, and four Rs may be the same or different for each other);
Indicates an integer of 4. And the general formula (IX) is

[0043]

Embedded image [Wherein, R ³ is the same as in the general formula (VIII), and Y ³ is
O ₃ is shown. And the general formula (X) is

[0044]

Embedded image [Wherein, R ³ is the same as in the general formula (VIII), R ′ represents a hydrocarbon group, an alkyloxy group, an aryloxy group or a hydroxyl group, n is an integer of 1 to 4, m is 1 to 3 Indicates an integer. ] Is represented.

Specific examples of such a quaternary phosphonium compound include, for example, tetraphenylphosphonium hydroxide, biphenyltriphenylphosphonium hydroxide, methoxyphenyltriphenylphosphonium hydroxide, phenoxyphenyltriphenylphosphonium hydroxide, naphthylphenyltriphenyl Phosphonium hydroxide, tetraphenylphosphonium tetraphenylborate, biphenyltriphenylphosphonium tetraphenylborate, methoxyphenyltriphenylphosphonium tetraphenylborate, phenoxyphenyltriphenylphosphonium tetraphenylborate, naphthylphenyltriphenylphosphonium tetraphenylborate, tetraphenylphosphonium phenoxide , Biff Nyltriphenylphosphonium phenoxide, methoxyphenyltriphenylphosphonium phenoxide, phenoxyphenyltriphenylphosphonium phenoxide, naphthylphenyltriphenylphosphonium phenoxide, tetraphenylphosphonium chloride, biphenyltriphenylphosphonium chloride, methoxyphenyltriphenylphosphonium chloride, phenoxyphenyltriphenylphosphonium Chloride or naphthylphenyltriphenylphosphonium chloride. Among the quaternary phosphonium salts of the component (b), from the viewpoint of the balance between the activity due to the thermal stability during the reaction and the quality of the obtained polycarbonate, particularly, tetraarylphosphonium tetraphenylborate, tetraarylphosphonium phenoxide,
Monoaryltriphenylphosphonium borate and monoaryltriphenylphosphonium phenoxide are preferred. That is, a quaternary phosphonium salt containing no alkyl group has excellent thermal stability and is effective for increasing the molecular weight at the latter stage of the reaction.

As the quaternary phosphonium salt of the component (b), one kind may be used, or two or more kinds may be used in combination. The nitrogen-containing organic basic compound as the component (a) and the quaternary phosphonium salt containing an aryl group as the component (b) preferably have a metal impurity content of 50 ppm or less, respectively. More preferably, the content of the earth metal compound is 30 ppm or less, particularly preferably 10 ppm or less. further,
The total amount of each metal impurity in the components (a) and (b) is 5% of the total amount of the components (a) and (b).
It is preferably 0 ppm or less, and the total content of the alkali metal and alkaline earth metal compounds in the component (a) and the component (b) is based on the total amount of the component (a) and the component (b). Those having 30 ppm or less are more preferred, and those having 10 ppm or less are particularly preferred. In the present invention, as a polymerization catalyst, the (a) nitrogen-containing organic basic compound as the component relative to a raw material for example dihydroxy compound, ^10-1 to ^10-8 mol, preferably ^10-2 to ^{- 7}
Mol, more preferably 10 ^-3 to 10 ^-6 mol,
(B) a quaternary phosphonium salt containing an aryl group as component (1)
It is desirable to use 0 ^-1 to 10 ^-8 mol, preferably 10 ^-2 to 10 ^-7 mol, more preferably 10 ^-3 to 10 ^-6 mol. If the amount of the component (a) is less than 10 ^-8 mol, the catalytic activity in the initial ^stage of the reaction will be insufficient, and if it exceeds 10 ^-1 mol, the cost will increase, which is not preferable. On the other hand, if the amount of the component (b) is less than 10 ^-8 mol, the catalytic activity in the latter half of the reaction will be insufficient, and if it exceeds 10 ^-1 mol, the cost will increase, which is not preferable.

The polymerization catalyst is used, for example, per mole of a dihydroxy compound (A) as a raw material.
The total amount of the component (a) and the component (b) is usually 2 × 10 ⁻¹
２2 × 10 ⁻⁸ mol, preferably 2 × 10 ⁻² to 2 × 10 ⁻⁷
Mol, more preferably 2 × 10 ⁻³ to 2 × 10 ⁻⁶ mol. The amount of the catalyst added is 2 ×
If the amount is less than 10 ^-8 mol, the catalytic effect may not be exhibited. If it exceeds 2 × 10 ⁻¹ mol, the physical properties of the final polycarbonate product, particularly heat resistance and hydrolysis resistance, may be reduced, leading to a cost increase. I will not do it. Further, in the present invention, the polymerization activity is enhanced by a combination of (a) a nitrogen-containing organic basic compound and (b) a quaternary phosphonium salt containing an aryl group as a polymerization catalyst. In the polycarbonate finally obtained, it is preferable to minimize the amount of metals that adversely affect the hydrolysis resistance and the coloring property. That is, the component (b) of the present invention substantially eliminates the use of a metal catalyst used in the latter half of the conventional reaction.

In the production method of the present invention, a raw material used for producing a polycarbonate by a usual transesterification method is used. Preferably, a dihydroxy compound as the component (A) and a carbonic acid diester as the component (B) are used. The transesterification reaction is carried out using a terminal terminator or a branching agent according to the above, and a polycarbonate having excellent quality can be obtained. Specifically, the reaction may be allowed to proceed according to a known transesterification method. Hereinafter, the procedure and conditions of the preferred production method of the present invention will be specifically described. First, the dihydroxy compound (A) and the carbonic acid diester (B) are
Carbonic acid diester is 0.9 to 1.
The transesterification reaction is performed at a ratio such that the molar ratio becomes 5 times. Note that, depending on the situation, the molar ratio is preferably 0.98 to 1.20 times.
In the above-mentioned transesterification reaction, the amount of the terminal terminator comprising the above-mentioned monohydric phenol is 0.05 to 10 mol% based on the dihydroxy compound as the component (A).
When it is in the range, the hydroxyl group terminal of the obtained polycarbonate is sealed, so that a polycarbonate sufficiently excellent in heat resistance and water resistance can be obtained. Such a terminal terminator comprising a monohydric phenol or the like may be added in advance to the reaction system in its entirety. Alternatively, a part may be added to the reaction system in advance, and the remainder may be added as the reaction proceeds. Further, in some cases, the whole amount may be added to the reaction system after the transesterification reaction between the dihydroxy compound of component (A) and the diester carbonate of component (B) partially proceeds.

In carrying out the transesterification according to the production method of the present invention, the reaction temperature is not particularly limited.
Usually in the range of 100 to 330 ° C, preferably 180 to 30 ° C.
The temperature is selected within the range of 0 ° C., and more preferably, the temperature is gradually raised to 180 to 300 ° C. in accordance with the progress of the reaction. The temperature of this transesterification reaction is 100 ° C
If the temperature is lower than 330 ° C., the reaction rate will be low. On the other hand, if the temperature exceeds 330 ° C., a problem such as side reaction will occur or the resulting polycarbonate will be colored, which is not preferable. The reaction pressure is set according to the vapor pressure of the monomer used and the reaction temperature. This may be set so that the reaction is performed efficiently, and is not limited. Usually, in the initial stage of the reaction, 1 to 50 atm (760 to 38,000)
torr) or pressurized state, and in the latter stage of the reaction, the pressure is reduced, preferably 0.01 to 100 torr in many cases. Furthermore, the reaction time may be performed until the target molecular weight is reached.
It is about 0.2 to 10 hours.

The above-mentioned transesterification is usually carried out in the absence of an inert solvent. If necessary, the ester exchange reaction may be carried out in the presence of an inert solvent of 1 to 150% by weight of the obtained polycarbonate. Good. Here, examples of the inert solvent include aromatic compounds such as diphenyl ether, halogenated diphenyl ether, benzophenone, polyphenyl ether, dichlorobenzene, and methylnaphthalene; tricyclo (5,2,10) decane, cyclooctane, and cyclodecane. And cycloalkane. If necessary, the reaction may be performed in an inert gas atmosphere. Examples of the inert gas include gases such as argon, carbon dioxide, nitrous oxide, and nitrogen, chlorofluorohydrocarbon, ethane, and propane. And alkenes such as ethylene and propylene.

In the present invention, if necessary, an antioxidant may be added to the reaction system. The antioxidant is preferably a phosphorus-based antioxidant, for example, trimethyl phosphite, triethyl phosphite, tributyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, trioctadecyl phosphite, distearyl. Trialkyl phosphites such as pentaerythyl diphosphite, tris (2-chloroethyl) phosphite, tris (2,3-dichloropropyl) phosphite, and tricycloalkyl phosphites such as tricyclohexyl phosphite;
Triaryl phosphites such as triphenyl phosphite, tricresyl phosphite, tris (ethylphenyl) phosphite, tris (butylphenyl) phosphite, tris (nonylphenyl) phosphite, and tris (hydroxyphenyl) phosphite; Monoalkyl diaryl phosphites such as ethylhexyl diphenyl phosphite, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, trioctadecyl phosphate, distearyl pentaerythrityl diphosphate, tris (2-chloroethyl) phosphate, Trialkyl phosphates such as tris (2,3-dichloropropyl) phosphate, tricyclohexyl phosphate What tricycloalkyl phosphate, triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate, 2
Triaryl phosphates such as -ethylphenyldiphenyl phosphate and the like.

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

In the present invention, after completion of the transesterification reaction, in order to improve the quality (coloring) of the obtained polycarbonate, the temperature is higher than the decomposition temperature of the catalyst, preferably 3
It is preferable to heat-treat the reactant at about 00 ° C. to thermally decompose and remove the catalyst. The polycarbonate obtained as described above may be granulated as it is, or may be molded using an extruder or the like. The polycarbonate obtained by the present invention can be used by blending known additives such as a plasticizer, a pigment, a lubricant, a release agent, a stabilizer, and an inorganic filler. Furthermore, this polycarbonate is made of polyolefin, polystyrene,
It can be blended with polymers such as polyester, polysulfonate, polyamide and polyphenylene ether. In particular, it is effective to use in combination with polyphenylene ether, polyether nitrile, terminal-modified polysiloxane compound, modified polypropylene, modified polystyrene or the like having OH group, COOH group, NH ₂ group or the like at the terminal. The polycarbonate obtained as described above was subjected to a steam resistance test (for example, a test conducted at a steam temperature of 121 ° C. for 4 hours).
Exposure for 8 hours to determine the decrease in viscosity average molecular weight), the hydrolysis resistance is such that the molecular weight decrease rate (ΔM / M ₀ × 100%: M ₀ is the initial molecular weight, ΔM is the molecular weight decrease) is 10% or less. Polycarbonate with excellent decomposability. Therefore, the polycarbonate obtained in the present invention can be preferably used for optical purposes, particularly for various information recording disks.

[0054]

Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. Examples 1 and 2 and Comparative Examples 1 to 3 22.8 g of bisphenol A (BPA) was placed in a nickel steel autoclave with a stirrer of 100 ml in internal volume.
(0.1 mol), 23.5 g of diphenyl carbonate (0.1
(1 mol) and the type and amount of catalyst shown in Table 1 were replaced with argon five times. Heating the mixture to 180 ° C.,
The reaction was performed for 30 minutes under an argon atmosphere. Then 210
℃, gradually increase the degree of vacuum to 100mmHg
The reaction was allowed to proceed for 0 minutes, and the temperature was further raised to 240 ° C., and the degree of vacuum was gradually increased to 10 mmHg to carry out the reaction for 30 minutes. Then 2
The temperature was raised to 70 ° C., the degree of vacuum was raised to 2 mmHg, and the reaction was carried out for 30 minutes. After that, the reaction was carried out at a degree of vacuum of 0.3 mmHg for 30 minutes to complete the reaction.

Next, the viscosity average molecular weight of the viscous and transparent condensate in the autoclave was determined, and the condensate was press-molded to form a plate having a thickness of 1 mm and a diameter of 10 mm. For 48 hours, the appearance and the decrease in viscosity average molecular weight were determined, and the steam resistance was evaluated. The results are shown in Table 1. The viscosity average molecular weight Mv
Was determined by calculating the intrinsic viscosity [η] in methylene chloride at 20 ° C. and calculating from the equation [η] = 1.23 × 10 ⁻⁵ × Mv ^0.83 .

Comparative Example 4 Tetrabutylphosphonium hydroxide (TBPH)
40% by weight aqueous solution (Na = 3ppm, K <1ppm)
The procedure was performed in the same manner as in Example 1 except that The results are shown in Table 1.

Comparative Example 5 Tetrabutylphosphonium hydroxide (TBPH)
40% by weight aqueous solution (Na = 66 ppm, K = 4pp
m) was carried out in the same manner as in Example 1 except that m) was used. The results are shown in Table 1.

[0058]

[Table 1]

[Note] TMAH: Tetramethylammonium hydroxide 2
0% by weight aqueous solution (Na <1 ppb, Ca <1 ppb, K
<1 ppb). TPTB: tetraphenylphosphonium tetraphenylborate (Na <1 ppm, Mg <1 ppm)

[0060]

[Table 2]

Examples 3 to 8 and Comparative Examples 6 to 8 In Example 1, the temperature was changed to 270 ° C. at the stage of the degree of vacuum of 0.3 mmHg.
, And carried out in the same manner as in Example 1 except that the temperature was changed to 290 ° C. Table 2 shows the type and amount of the catalyst and the test results.

Examples 9 and 10 The same procedures as in Example 1 were carried out except that the reaction was carried out at 270 ° C. and a degree of vacuum of 0.3 mmHg for 30 minutes, followed by a heat treatment at 290 ° C. and a degree of vacuum of 0.3 mmHg for 10 minutes. Performed in the same manner as in Example 1. Table 2 shows the type and amount of the catalyst and the test results.

[0063]

[Table 3]

[Note] TMAH: Tetramethylammonium hydroxide 2
0% by weight aqueous solution (Na <1 ppb, Ca <1 ppb,
K <1 ppb). BPTB: biphenyltriphenylphosphonium tetraphenylborate (Na <1 ppm, Ca <1 ppm,
K <1 ppm) POPTB: phenoxyphenyltriphenylphosphonium tetraphenylborate (Na <1 ppm, Ca <
1 ppm, K <1 ppm) MOPTB: methoxyphenyltriphenylphosphonium tetraphenylborate (Na <1 ppm, Mg <1
ppm) BPPO: biphenyltriphenylphosphonium phenoxide (Na <1 ppm, Ca <1 ppm, K <1pp
m) POPPO: phenoxyphenyltriphenylphosphonium phenoxide (Na <1 ppm, Ca <1 ppm,
K <1 ppm) MOPPO: methoxyphenyltriphenylphosphonium phenoxide (Na <1 ppm, Ca <1 ppm, K
<1 ppm) TPTB: tetraphenylphosphonium tetraphenylborate (Na <1 ppm, Mg <1 ppm)

[0065]

[Table 4]

[0066]

According to the present invention, in the production of polycarbonate by transesterification, as a polymerization catalyst,
By using a combination of a nitrogen-containing organic basic compound and a quaternary phosphonium salt containing an aryl group, the catalyst activity is sufficiently high, the reaction rate can be improved, and the removal by thermal decomposition of the catalyst at the final stage of the reaction is prevented. It is possible to efficiently produce a high-quality polycarbonate excellent in heat resistance and hydrolysis resistance and having good color tone.

Claims (15)

[Claims] In producing a polycarbonate by an ester conversion reaction, a combination of (a) a nitrogen-containing organic basic compound and (b) a quaternary phosphonium salt containing an aryl group is used as a polymerization catalyst. Method for producing polycarbonate. 2. The method according to claim 1, wherein the nitrogen-containing organic basic compound is a quaternary ammonium salt. 3. A nitrogen-containing organic basic compound is represented by the general formula _{^{(I) (NR 1 4)}} + (X 1) - ··· (I) [In the formula, R ¹ represents an organic group, four R ¹ may be the same or different, and two R ¹ may combine to form a ring structure. X ¹ is a halogen atom, a hydroxyl group, an alkyloxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, H
CO ₃ or BR ₄ (R represents a hydrogen atom or a hydrocarbon group, and four Rs may be the same or different.)
Is shown. ] Or the general formula _{^{(II) (NR 1 4)}} + 2 (Y 1) 2- ··· (II) wherein, R ¹ is the same as in the general formula (I), Y ¹ is CO
_{Shows 3} . ] Alternatively, the formula (III) [(NR ¹ ₄₎ ⁺ O ^-] _{n -P (= O) R '} 3-n ··· (III) wherein, R ¹ is the same as in the general formula (I) R ′ represents a hydrocarbon group, an alkyloxy group, an aryloxy group or a hydroxyl group, R ′ may be the same or different, and n represents an integer of 1 to 3. 3. The method for producing a polycarbonate according to claim 1, wherein the quaternary ammonium salt is dimethylaminopyridine. Wherein the quaternary phosphonium salt is represented by the general formula _{^{(IV) (PR 2 4)}} + (X 2) - ··· (IV) : wherein, R ² is an organic group, four R ² At least one of them is an aryl group. The four R ^{2 s} may be the same or different, and two R ^2s may combine to form a ring structure. X ² is a halogen atom,
Hydroxyl, alkyloxy, aryloxy, alkylcarbonyloxy, arylcarbonyloxy,
HCO ₃ or BR ₄ (R represents a hydrogen atom or a hydrocarbon group, and four Rs may be the same or different.)
Is shown. ] Or the general formula _{^{(V) (PR 2 4)}} + 2 (Y 2) 2- ··· (V) wherein, R ² is the same as in the general formula (IV), Y ² is CO
_{Shows 3} . ] Alternatively, the formula (VI) [(PR ² ₄₎ ⁺ O ^-] _{n -P (= O) R '} 3-n ··· (VI) wherein, R ² is the same as in the general formula (IV) R ′ represents a hydrocarbon group, an alkyloxy group, an aryloxy group or a hydroxyl group, R ′ may be the same or different, and n represents an integer of 1 to 3. The method for producing a polycarbonate according to claim 1, which is a compound represented by the formula: 5. The cation component of a quaternary phosphonium salt,
General formula (VII) [In the formula, R ³ represents an organic group, which may be the same or different, and n represents an integer of 0 to 4. The method for producing a polycarbonate according to claim 1, which is a compound represented by the formula: 6. A quaternary phosphonium salt represented by the general formula (VIII): Wherein R ³ represents an organic group, which may be the same or different, and X ³ represents a halogen atom, a hydroxyl group, an alkyloxy group, an aryloxy group, an alkylcarbonyloxy group, an arylcarbonyloxy group, HCO ₃ Or BR
₄ (R represents a hydrogen atom or a hydrocarbon group, and four Rs may be the same or different for each other);
Indicates an integer of 4. Or the general formula (IX): [Wherein, R ³ is the same as in the general formula (VIII), and Y ³ is
O ₃ indicates, n represents an integer of 0-4. Or the general formula (X): Wherein R ³ represents an organic group, which may be the same or different, and R ′ represents a hydrocarbon group, an alkyloxy group,
Represents an aryloxy group or a hydroxyl group, n is an integer of 1 to 4,
m shows the integer of 1-3. The method for producing a polycarbonate according to claim 1, which is a compound represented by the formula: 7. Component (a) or (b) as a polymerization catalyst
The method for producing a polycarbonate according to claim 1, wherein a catalyst having a metal impurity content of 50 ppm or less is used. 8. The method for producing a polycarbonate according to claim 1, wherein the raw materials for the transesterification reaction are (A) a dihydroxy compound and (B) a carbonic acid diester. 9. The dihydroxy compound as component (A),
The method for producing a polycarbonate according to claim 1, which is 2,2-bis (4-hydroxyphenyl) propane. 10. The method for producing a polycarbonate according to claim 1, wherein the carbonate diester of the component (B) is diphenyl carbonate. 11. The process for producing a polycarbonate according to claim 1, wherein after the reaction is completed, the reaction product is heat-treated at a temperature not lower than the decomposition temperature of the catalyst. 12. The polycarbonate according to claim 5, wherein component (a) is tetramethylammonium hydroxide and component (b) is tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium phenolate or tetraphenylphosphonium hydroxide. Production method. 13. The component (a) is tetramethylammonium hydroxide, and the component (b) is biphenyltriphenylphosphonium tetraphenylborate, phenoxyphenyltriphenylphosphonium tetraphenylborate, methoxyphenyltriphenylphosphonium tetraphenylborate, biphenyl. The method for producing a polycarbonate according to claim 5, which is at least one compound selected from the group consisting of triphenylphosphonium phenoxide, phenoxyphenyltriphenylphosphonium phenoxide, and methoxyphenyltriphenylphosphonium phenoxide. 14. The method for producing a polycarbonate according to claim 1, wherein in a steam resistance test of the obtained polycarbonate, a molecular weight reduction rate is 10% or less. 15. An optical polycarbonate obtained by the method according to claim 1. Description: