JPH0912704A - Method for producing polycarbonate - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the coloring resistance and hydrolysis resistance of a polymer in a method for producing a polycarbonate by a transesterification method in the presence of a catalyst. A method for producing a polycarbonate using a quaternary phosphonium salt containing a branched alkyl group as a reaction catalyst in producing a polycarbonate by a transesterification reaction.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a polycarbonate by a transesterification reaction using a specific catalyst. More specifically, the present invention relates to a method for producing a polycarbonate using a specific quaternary phosphonium salt as a reaction catalyst when producing a polycarbonate by a transesterification reaction such as a transesterification reaction between a dihydroxy compound and a carbonic acid diester.

[0002]

2. Description of the Related Art Polycarbonate has excellent transparency and heat resistance as well as impact resistance, and is now widely used as a so-called engineering plastic in the fields of electricity, electronics, automobiles, optical parts, and other industrial fields. There is. Generally, as a main production method of polycarbonate (hereinafter sometimes referred to as PC), there are roughly classified two types of methods, one of which is an aromatic dihydroxy compound such as bisphenol A and phosgene. A direct reaction method (usually called an interfacial polycondensation method), and another method is a method of transesterifying an aromatic dihydroxy compound and a carbonic acid diester such as diphenyl carbonate in a molten state (usually a melt polymerization method or a transesterification method). It is known that there are differences in the physical properties of the obtained polymers as well as differences in the production method, and the above-mentioned production methods are properly used according to various conditions and purpose of use of the polymer. There is.

The above-mentioned interfacial polycondensation method requires the use of toxic phosgene, the need to take measures to prevent corrosion of manufacturing equipment by chlorine-containing compounds (hydrogen chloride, sodium chloride, etc.) that are by-produced, and There are many problems such as difficulty in separating impurities (sodium hydroxide, etc.) that adversely affect the physical properties. On the other hand, the transesterification method (melt polymerization method) is
At present, it is considered to be a cheaper manufacturing method, and is also an excellent manufacturing method in that phosgene gas and methylene chloride as a solvent are not used.

However, in the production of PC by the transesterification method (melt polymerization method), a basic catalyst such as an alkali metal or alkaline earth metal carbonate or acetate is used as a reaction catalyst, and usually 280 to 310. It has been pointed out that the polymer is low in hydrolysis resistance and inferior in thermal stability because the reaction is carried out at a high temperature of ℃ for a long time.

Recently, some proposals have been made to solve the problems based on the use of a basic catalyst in the transesterification method. For example, a method using a catalyst composed of a nitrogen-containing basic compound and an alkali metal or an alkaline earth metal (JP-A-2-124934), an electron-donating amine compound and an element of Group IIb, Ib or Vb of the periodic table. Using a catalyst composed of a compound containing
No. 145) is disclosed, but a catalyst such as an alkali metal remains in the final product polycarbonate,
The problems of deterioration of physical properties such as heat resistance and hydrolysis resistance have not been fully solved. Further, a method using a specific catalyst (Japanese Patent Publication No. 61-39972, JP-A No. 63-22303).
No. 6, etc.) are also disclosed, but the problems related to the present invention have not been solved.

Further, as a method for solving the problem from the viewpoint of preventing oxidation, a method of adding an antioxidant in the latter stage of the transesterification reaction (JP-A-61-151236 and JP-A-62-1587).
No. 19, etc.), a twin-screw vent type kneading extruder in the latter stage of the reaction (Japanese Patent Laid-Open No. 61-62522, etc.), or a horizontal stirring polymerization tank (Japanese Patent Laid-Open No. 2-15).
No. 3925, etc.) has been proposed, and as a method for solving the problem by neutralizing the basic catalyst, there is a method of adding an acidic substance to the reaction system at the end of the reaction, and dimethyl sulfuric acid has been conventionally used. However, recently, a method of neutralizing using an acid such as p-toluenesulfonic acid and capturing an excess acid with an epoxy compound (Japanese Patent Laid-Open No. 4-175368) is disclosed. However, new problems such as the need to further detoxify the excess acidic substance used for neutralization have arisen, and none of these can solve the above-mentioned problems of the present invention.

On the other hand, a technique of using a quaternary phosphonium salt as a catalyst (Japanese Patent Publication No. Sho 47-17978, JP-A-6-2).
56497, 6-200009, 6-2069.
Japanese Patent No. 96 etc.) is also disclosed, but used tetra long-chain alkylphosphonium salt (having 4 or more carbon atoms)
Has a problem that the catalytic activity in the latter stage of the transesterification reaction is low, and the tetraarylphosphonium salt has a problem that various qualities of the polymer are deteriorated due to the catalyst residue.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to improve the coloring resistance and hydrolysis resistance of a polymer in a method for producing a polycarbonate by a transesterification method in the presence of a catalyst. More specifically, it is intended to improve the above properties by using a new catalyst.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned problems, and as a result, have
It was found that the above problem can be solved by causing a transesterification reaction using a primary phosphonium salt, and completed the present invention. That is, the gist of the present invention is as follows.

(1) A method for producing a polycarbonate using a quaternary phosphonium salt containing a branched alkyl group as a reaction catalyst in producing a polycarbonate by a transesterification reaction. (2) The method for producing a polycarbonate according to the above 1, wherein the raw materials for the transesterification reaction are a dihydroxy compound and a carbonic acid diester. (3) The polycarbonate according to the above 1 or 2, wherein the quaternary phosphonium salt containing a branched alkyl group is at least one selected from compounds represented by the general formula (I) and the general formula (II). Production method.

[0011]

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[Here, n is an integer of 1 to 4. However, when n is plural, the branched alkyl groups may be the same as or different from each other. R ^{1 to} R ³ : at least one selected from hydrogen, an alkyl group, an alkyl group having a substituent, an aryl group and an aryl group having a substituent, and at least two of R ^{1 to} R ³ are bonded to form a ring. It may form a structure. However, this excludes the case where two are hydrogen at the same time. R ⁴ : an alkyl group, an alkyl group having a substituent,
An aryl group or an aryl group having a substituent. X: OH, RO, BH ₄ , BR ₄ , RCOO, a halogen atom or HCO ₃ . Here, R is an alkyl group, an alkyl group having a substituent, an aryl group,
Alternatively, it is an aryl group having a substituent. Y: CO ₃ . ] (Fourth) The above first using a nitrogen-containing organic base together with the reaction catalyst
4. The method for producing a polycarbonate according to any one of 3 to 3.

Hereinafter, the contents of the present invention will be described in detail. First, in the present invention, when a polycarbonate is produced by a transesterification reaction, the raw material used for the transesterification reaction is not particularly limited, and various materials used for production by a usual transesterification method are used. . For example, in a transesterification reaction, a dihydroxy compound as the component (A), a carbonic acid diester as the component (B), a diester of a dihydroxy compound as the component (A) and a carbonic acid diester as the component (B),
As the component (A), a dicarbonic acid ester of a dihydroxy compound and as the component (B), a carbonic acid diester, a dicarbonic acid ester of a dihydroxy compound (self-condensation), a monocarbonic acid ester of a dihydroxy compound (self-transesterification) and the like can be mentioned. Among these, a dihydroxy compound as the component (A) and a carbonic acid diester as the component (B) are preferably used.

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

[0015]

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[In the formula, R ⁵ and R ⁶ are each independently a halogen atom (eg, chlorine, bromine, fluorine, iodine) or an alkyl group having 1 to 8 carbon atoms (eg, methyl group, ethyl group, propyl group). , N-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, etc.)
^When either or both of ⁵ and R ⁶ are plural, they may be the same or different from each other, m
And n are each independently an integer of 0 to 4. Z is a single bond, an alkylene group having 1 to 8 carbon atoms or an alkylidene group having 2 to 8 carbon atoms (for example, methylene group, ethylene group, propylene group, butylene group, penterylene group, hexylene group, ethylidene group, isopropylidene group) Etc.), a cycloalkylene group having 5 to 15 carbon atoms or a cycloalkylidene group having 5 to 15 carbon atoms (for example, a cyclopentylene group, a cyclohexylene group, a cyclopentylidene group, a cyclohexylidene group, etc.), or -S- , -SO-, -SO
_2- , -O-, -CO- bond or formula (IV) or
(V)

[0017]

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The bond represented by ] The aromatic dihydroxy compound represented by these is mentioned. Specific examples of such aromatic dihydroxy compounds include bis (4-hydroxyphenyl) methane; bis (3-methyl-4-hydroxyphenyl) methane; 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 called 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-)
2,2-bis (4-hydroxyphenyl) butane; 2,2-bis (4-hydroxyphenyl) octane; 2,2-bis (4-hydroxyphenyl) phenylmethane; 2,2-bis (4-Hydroxy-1-methylphenyl) propane; 1,1-bis (4-hydroxy-t-butylphenyl) propane;
2,2-bis (4-hydroxy-3-bromophenyl)
Propane; 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane; 2,2-bis (4-hydroxy-3-chlorophenyl) propane; 2,2-bis (4-hydroxy-3,5) -Dichlorophenyl) propane; 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane; 2,2-bis (3-bromo-4-)
Hydroxy-5-chlorophenyl) propane; 2,2-
Bis (3-phenyl-4-hydroxyphenyl) propane; 2,2-bis (4-hydroxyphenyl) butane;
2,2-bis (3-methyl-4-hydroxyphenyl)
Butane; 1,1-bis (2-butyl-4-hydroxy-
5-methylphenyl) butane; 1,1-bis (2-t-
Butyl-4-hydroxy-5-methylphenyl) butane; 1,1-bis (2-tert-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 , 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-hydroxyphenyl) cyclohexane; 1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane; 1,1-bis (4-hydroxyphenyl)-
Bis (hydroxyaryl) cycloalkanes such as 3,5,5-trimethylcyclohexane; bis (4-hydroxyphenyl) ether; bis (4, -hydroxy-)
Bis (hydroxyaryl) ethers such as 3-methylphenyl) ether; Bis (4-hydroxyphenyl) sulfide; Bis (hydroxyaryl) such as bis (3-methyl-4-hydroxyphenyl) sulfide
Sulfides; Bis (4-hydroxyphenyl) sulfoxide; Bis (3-methyl-4-hydroxyphenyl)
Sulfoxides; bis (hydroxyaryl) sulfoxides such as bis (3-phenyl-4-hydroxyphenyl) sulfoxide; bis (4hydroxyphenyl) sulfone; bis (3-methyl-4-hydroxyphenyl)
Sulfones; bis (hydroxyaryl) sulfones such as bis (3-phenyl-4-hydroxyphenyl) sulfone, 4,4'-dihydroxybiphenyl;4,4'-
Dihydroxy-2,2'-dimethylbiphenyl; 4,
4'-dihydroxy-3,3'-dimethylbiphenyl;
4,4'-dihydroxy-3,3'-dicyclohexylbiphenyl; and dihydroxybiphenyls such as 3,3'-difluoro-4,4'-dihydroxybiphenyl.

Examples of aromatic dihydroxy compounds other than the above general formula (III) include dihydroxybenzenes, halogen- and alkyl-substituted dihydroxybenzenes.
For example, resorcin, 3-methylresorcin, 3-ethylresorcin, 3-propylresorcin, 3-butylresorcin, 3-t-butylresorcin, 3-phenylresorcin, 3-cumylresorcin; 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; 2,3,5,6-tetrabromohydroquinone and the like.

There are various kinds of aliphatic dihydroxy compounds used as one of the dihydroxy compounds as the component (A). For example, butane-1,4-diol; 2,2-dimethylpropane-1,3-diol;
Hexane-1,6-diol; diethylene glycol;
Triethylene glycol; tetraethylene glycol;
Octaethylene glycol; dipropylene glycol;
N, N-methyldiethanolamine; cyclohexane-
1,3-diol; cyclohexane-1,4-diol; 1,4-dimethylolcyclohexane; p-xylylene glycol; 2,2-bis- (4-hydroxycyclohexyl) -propane and ethoxy of dihydric alcohol or phenol And propoxylated products such as bis-oxyethyl-bisphenol A; bis-oxyethyl-tetrachlorobisphenol A or bis-oxyethyl-tetrachlorohydroquinone.

In a preferred production method of the present invention,
The above-mentioned compounds are appropriately selected and used as the dihydroxy compound as the component (A). Among these, aromatic dihydroxy compounds are preferably used in view of mechanical properties, heat resistance and the like. Among them, bisphenol A is particularly preferable. Is most suitable because it has an excellent balance of physical properties. Further, an aromatic dihydroxy compound and an aliphatic dihydroxy compound can be used in combination, and a high fluidity polycarbonate can be obtained.

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

[0023]

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[In the formula, Ar ² represents an aryl group. ] Or a compound represented by the general formula (VII)

[0025]

[Chemical 6]

[In the formula, Ar ¹ represents a residue obtained by removing two hydroxyl groups from the aromatic dihydroxy compound, and Ar ² is the same as above. ] It is a compound represented by these. The dialkyl carbonate compound has the general formula (VIII)

[0027]

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[In the formula, R ⁷ and R ⁸ are each independently an alkyl group having 1 to 6 carbon atoms or 4 to 4 carbon atoms.
A cycloalkyl group having 7 is shown. ] Or a compound represented by the general formula (IX)

[0029]

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[In the formula, R ⁷ , R ⁸ and Ar ¹ are the same as defined above. ] It is a compound represented by these. The alkyl aryl carbonate compound has the general formula (X)

[0031]

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[In the formula, Ar ² is the same as the above, and R ⁹ is the same as the above R ⁷ or R ⁸ . ] Or a compound represented by the general formula (XI)

[0033]

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[In the formula, Ar ¹ and Ar ² are the same as above, and R ⁹ is the same as above. ] It is a compound represented by these. Here, as specific examples of the diaryl carbonate compound,
Diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl)
Examples thereof include carbonate and bisphenol A bisphenyl carbonate. Examples of the dialkyl carbonate compound include diethyl carbonate, dimethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, bisphenol A bismethyl carbonate and the like. Examples of the alkyl aryl carbonate compound include, 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 transesterification reaction according to the present invention, when a dihydroxy compound is used as the component (A), it is preferable to use a carbonic acid diester as the component (B) from the viewpoint of easy purification of the raw material. Are used by appropriately selecting from the above compounds, and among these, diphenyl carbonate is most preferably used from the viewpoint of reactivity.

The raw materials used in the present invention include:
The dihydroxy compounds and the carbonic acid diesters are preferably used, but as the raw materials which can be used other than these, the following are mentioned. That is, examples of diesters of dihydroxy compounds include bisphenol A diacetate, bisphenol A dipropionate, bisphenol A dibutyrate, and bisphenol A dibenzoate. Examples of dicarbonic acid esters of dihydroxy compounds include bisphenol carbonic acid ester of bisphenol A, bisethyl carbonic acid ester of bisphenol A, and bisphenyl carbonic acid ester of bisphenol A. Examples of monocarbonic acid esters of dihydroxy compounds include bisphenol A monomethyl carbonic acid ester, bisphenol A monoethyl carbonic acid ester, bisphenol A monopropyl carbonic acid ester, and bisphenol A monophenyl carbonic acid ester.

In the production method of the present invention, an end terminating agent can be used if necessary, and specific examples thereof include on-n-butylphenol; mn-butylphenol; pn-butylphenol; o-isobutylphenol; m-isobutylphenol; p-isobutylphenol; ot-butylphenol; mt-butylphenol; pt-butylphenol; on-pentylphenol; m-n-pentylphenol; pn
-Pentylphenol; on-hexylphenol;
mn-hexylphenol; pn-hexylphenol; o-cyclohexylphenol; m-cyclohexylphenol; p-cyclohexylphenol; o-
Phenylphenol; m-phenylphenol; p-phenylphenol; on-nonylphenol; mn
-Nonylphenol; pn-nonylphenol; o-
Cumylphenol; m-cumylphenol; p-cumylphenol; o-naphthylphenol; m-naphthylphenol; p-naphthylphenol; 2,6-di-t-
Butylphenol; 2,5-di-t-butylphenol; 2,4-di-t-butylphenol; 3,5-di-
t-butylphenol; 2,5-dicumylphenol;
3,5-dicumylphenol; formula

[0037]

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Examples of various compounds and chroman derivatives represented by

[0039]

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Various monohydric phenols such as compounds represented by Of these phenols, although not particularly limited in the present invention, p-tert-butylphenol; p-cumylphenol; p-phenylphenol and the like are preferable. Furthermore, the compound represented by the following general formula can be appropriately selected and used.

[0041]

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Further, a branching agent may be added to the ester reaction system according to the present invention as needed, and the branching agent is phloroglucin; trimellitic acid;
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 be used.

In the transesterification reaction according to the present invention, a quaternary phosphonium salt containing a branched alkyl group is used as a catalyst. Here, 4 containing a branched alkyl group
The quaternary phosphonium salt comprises, as shown in the general formulas (I) and (II), a quaternary phosphonium cation containing a branched alkyl group and X ⁻ or Y ^{2 −} as a counter anion, each of which has various kinds. Can be used.

Specific examples of the quaternary phosphonium containing a branched alkyl group include isopropyltrimethylphosphonium; isopropyltriethylphosphonium; isopropyltributylphosphonium; isopropyltriphenylphosphonium; tetraisopropylphosphonium; cyclohexyltriethylphosphonium; cyclohexyltrimethylphosphonium; cyclohexyltributylphosphonium; Cyclohexyltriphenylphosphonium;
Tetracyclohexylphosphonium; 1,1,1-triphenylmethyltrimethylphosphonium; 1,1,1-
Triphenylmethyltriethylphosphonium; 1,1,
1-triphenylmethyltributylphosphonium; 1,
Mention may be made of 1,1-triphenylmethyltriphenylphosphonium.

Specific examples of X relating to the counter anion include hydroxide; borohydride; tetraphenylborate; acetate; propionate; fluoride; chloride; carbonate and the like. Specific examples of Y include carbonate.

Specific examples of the salt composed of a quaternary phosphonium (cation) having a branched alkyl group and X or Y (anion) include various combinations of the above-mentioned specific examples. Examples include phosphonium hydroxide; cyclohexyltriphenylphosphonium chloride; 1,1,1-triphenylmethyltriethylphosphonium acetate; bis (isopropyltriethylphosphonium) carbonate. Among these quaternary phosphonium salts containing a branched alkyl group, cyclohexyltriphenylphosphonium tetraphenylborate and cyclopentyltriphenylphosphonium tetraphenylborate are particularly preferably used because they are excellent in the balance between the catalytic effect and the quality of the obtained polycarbonate. .

When a dihydroxy compound is used as a raw material for transesterification reaction, the amount of the catalyst is usually 10 ^-1 to 10 ^-8 mol / mole based on the dihydroxy compound.
Molar is preferable, and 10 ^-2 to 10 ^-7 mol / mol is more preferable. If the amount of this catalyst used is less than 10 ^-8 mol / mol,
There is a possibility that the catalytic effect is not exhibited. Further, if it exceeds 10 ^-1 mol / mol, the physical properties of the final product polycarbonate, particularly heat resistance and hydrolysis resistance, may be deteriorated, and it may lead to an increase in cost. There is nothing to do. The catalytic effect is 10 ^-2 to 10 ^-7
It becomes clearer in the mol / mol range.

The above-mentioned reaction catalyst may be used in combination with a nitrogen-containing organic basic compound to improve the hydrolysis resistance of the polycarbonate, but the nitrogen-containing organic basic compound referred to here is not particularly limited. , There are various things. For example, tetramethylammonium hydroxide (Me ₄ NOH), tetraethylammonium hydroxide (Et ₄ NOH), tetrabutylammonium hydroxide (Bu ₄ NOH), trimethylbenzylammonium hydroxide [C ₆ H ₅ CH ₂ (Me) ₃ NOH] and the like, ammonium hydroxides having an alkyl group, an aryl group, an araryl group, etc., tetramethylammonium borohydride (Me ₄ NBH ₄ ), tetrabutylammonium borohydride (Bu ₄ NBH ₄ ),
Tetrabutylammonium phenylborate (Bu ₄ N
Basic salts such as BPh ₄ ), tetramethylammonium tetraphenylborate (Me ₄ NBPh ₄ ) and the like can be mentioned.
In addition, 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
-Nitrogen-containing heterocyclic compounds such as mercaptoimidazole, aminoquinoline, and diazabicyclooctane (DABCO). Further, there may be mentioned aliphatic tertiary amine compounds such as trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine and dimethylbenzylamine, and aromatic tertiary amine compounds such as triphenylamine. .

Among these basic compounds, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetramethylammonium borohydride, tetrabutylammonium borohydride and the like are preferably used in terms of catalytic activity and quality of the obtained polycarbonate. To be In addition, the basic compound has a characteristic of relatively low residual property in the reaction system.

When the dihydroxy compound is used in the transesterification reaction, the amount of the above nitrogen-containing organic basic compound used is the same as that of the quaternary phosphonium salt containing a branched alkyl group. In general, 10 ^-1 to 10 ^-8 mol / mol is preferable, and 10
^It is more preferably ^-2 to 10 ^-7 mol / mol. If the amount of the basic compound used is less than 10 ^-8 mol / mol, the combined effect may not be exhibited. If it exceeds 10 ^-1 mol / mol, the physical properties of the final product, polycarbonate,
In particular, there is a possibility that heat resistance and hydrolysis resistance may be significantly lowered, and it also leads to an increase in cost. The combined effect with a quaternary phosphonium salt containing a branched alkyl group as a catalyst is 10 ^-2 ~
It becomes clearer in the range of 10 ⁻⁷ mol / mol. The nitrogen-containing organic basic compound and the quaternary phosphonium salt are preferably those containing as little metal impurities as possible, and particularly preferably those containing 50 ppm or less of the alkali metal and alkaline earth metal compounds. is there.

In the method for producing a polycarbonate according to the present invention, a raw material used for producing a polycarbonate by a normal transesterification method, preferably a dihydroxy compound as the component (A) and a carbonic acid diester as the component (B) are used. However, if necessary, a terminal stopper, a branching agent or the like may be added and used to obtain a polycarbonate of excellent quality. Specifically, the reaction may be allowed to proceed according to a known transesterification method. Hereinafter, an example of the procedure and conditions of the preferred production method of the present invention will be specifically shown. First, (A)
The dihydroxy compound as the component and the carbonic acid diester as the component (B), and the carbonic acid diester as the dihydroxy compound.
Transesterification is carried out at a ratio such that the molar ratio is 0.95 to 1.5 times. Depending on the situation, the amount of carbonic acid diester may be slightly excessive with respect to the dihydroxy compound.
A molar amount of 1.02 to 1.20 times may be preferable. In the above-mentioned transesterification reaction, the amount of the terminal terminating agent consisting of the monohydric phenol or the like is in the range of 0.05 to 10 mol% with respect to 1 mol of the dihydroxy compound as the component (A), Since the hydroxyl group terminal of the obtained polycarbonate is sealed, a polycarbonate having excellent heat resistance and water resistance can be obtained. The total amount of the above-mentioned end-capping agent composed of monohydric phenol may be added to the reaction system in advance, but a part thereof may be added to the reaction system in advance and the rest may be added as the reaction progresses. You may. Further, in some cases, the whole amount may be added to the reaction system after the transesterification reaction of the dihydroxy compound (A) and the carbonic acid diester (B) partially proceeds.

In carrying out the transesterification reaction according to the present invention, the reaction temperature is not particularly limited, but usually 10
It is in the range of 0 ° C to 330 ° C, preferably 130 ° C to 3
The temperature range is 00 ° C. When the temperature of this transesterification reaction is less than 100 ° C, the reaction rate becomes slow, while
If the temperature exceeds 30 ° C, side reactions may occur, or the generated polycarbonate may be colored, which is not preferable in some cases. It is preferable that the temperature is 130 to 300 ° C., because the above-mentioned problems do not tend to occur. The reaction pressure is set according to the vapor pressure of the monomer used and the reaction temperature, and is not particularly limited, but in order to carry out the reaction efficiently, usually in the initial stage of the reaction,
The atmospheric pressure (normal pressure) up to 1 to 50 atm (760 to 38,000 torr) or the pressurized state is kept, and the pressure is reduced in the latter stage of the reaction, preferably 0.01 to 100 tons finally.
It is performed under the condition of rr. Further, the reaction time may be such that it reaches the target molecular weight, and is usually about 0.2 to 10 hours.

The above transesterification reaction is usually carried out in the absence of an inert solvent, but if necessary, it may be carried out in the presence of 1 to 150% by weight of the obtained PC of an inert solvent. Good. Here, examples of the inert solvent include aromatic compounds such as diphenyl ether, halogenated diphenyl ether, benzophenone, polyphenyl ether, dichlorobenzene, methylnaphthalene, gases such as carbon dioxide, dinitrogen monoxide and nitrogen, and chlorofluorohydrocarbons. Examples thereof include alkanes such as ethane and propane, cyclohexane such as cyclohexane, tricyclo (5.2.10) decane, cyclooctane and cyclodecane, and alkenes such as ethene and propene.

The transesterification reaction according to the present invention is
It can be carried out in the presence of an antioxidant, if necessary. Specific examples of phosphorus-based antioxidants to be used include tri (nonylphenyl) phosphite, 2-ethylhexidiphenylphosphite, trimethylphosphite, triethylphosphite, and tributylphosphite. , Trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, trioctadecyl phosphite, distearyl pentaerythryl diphosphite, tris (2-chloroethyl) phosphite, tris (2,3-dichloropropyl) phosphite Trialkyl phosphite such as; tricycloalkyl phosphite such as tricyclohexyl phosphite; triphenyl phosphite, tricresyl phosphite, tris (ethylphenyl) phosphite, tris (butylphenyl) phos Triaryl phosphites such as bisulfite, tris (nonylphenyl) phosphite, tris (hydroxyphenyl) phosphite; trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, trioctadecyl phosphate, distearyl pentaerythrityl Diphosphate, Tris (2
Trialkyl phosphates such as -chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate; tricycloalkyl phosphates such as tricyclohexyl phosphate; triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate, 2-ethyl Examples include triaryl phosphates such as phenyldiphenyl phosphate.

In the transesterification reaction according to the present invention,
When a carbonic acid diester is used, phenols, alcohols, or their esters and an inert solvent corresponding to the carbonic acid diester are desorbed 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 reaction according to 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. Also,
The material and structure of the reactor used in the above reaction are not particularly limited, but it is sufficient that the reactor has 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.

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

[0057]

The present invention will be further described in detail with reference to Examples and Comparative Examples. The present invention is not limited to the examples below. Examples 1 to 5, Comparative Examples 1 to 4 Bisphenol A (BPA) 22.8 was added to a nickel steel autoclave with an agitator having an internal volume of 100 ml.
g (0.1 mol), diphenyl carbonate 23.5 g (0.1
11 mol) and the catalysts shown in Table 1 were charged in predetermined amounts, and nitrogen substitution was carried out 5 times. The mixture was heated to 180 ° C. and reacted for 30 minutes under an argon atmosphere. Next, the temperature is raised to 210 ° C., the degree of vacuum is gradually raised to 100 mmHg, the reaction is carried out for 30 minutes, the temperature is further raised to 240 ° C., and the degree of vacuum is gradually increased to 1
After the pressure was raised to 0 mmHg and reacted for 30 minutes, the degree of vacuum was raised to 2 mmHg and further reacted for 30 minutes. Then 26
After heating to 0 ° C. and reacting for 30 minutes, the temperature was raised to 270 ° C., the degree of vacuum was raised to 0.3 mmHg, and the reaction was further performed for 30 minutes. A viscous, transparent reaction remained in the autoclave. Dissolve this reaction product in methylene chloride and
Was measured, and the viscosity average molecular weight was calculated from the following formula [η] = 1.23 × 10 ⁻⁵ × Mv ^0.83 . The appearance and hydrolysis resistance of the obtained molded product of the reaction product were evaluated by molding a plate having a thickness of 1 mm and a diameter of 10 mm and exposing it to 121 ° C. steam for 48 hours. Hydrolysis resistance here is
It was evaluated based on the degree of molecular weight reduction. Furthermore, the retention burn test for the molded product was conducted under a nitrogen gas stream for 3 days.
After heating at 40 ° C for 1.5 hours, add 8% by weight to methylene chloride.
It melt | dissolved so that it might become, and it was performed by measuring YI with the color meter SM-3 (made by Suga Test Instruments Co., Ltd.) using the quartz cell of 57 mm of optical path lengths. The amounts of the catalyst and the nitrogen-containing organic base compound used, and the results of measurement and evaluation are shown in Table 1.

Examples 6 to 7 In Example 1, the temperature was raised to 240 ° C., the degree of vacuum was gradually raised to 10 mmHg, the reaction was carried out for 30 minutes, and the reaction conditions were changed to 2 mmHg instead of 270. The reaction was carried out in the same manner as in Example 1 except that the reaction was conducted at 30 ° C. for another 30 minutes, then the temperature was raised to 290 ° C., the vacuum degree was raised to 0.5 mmHg, and the reaction was conducted for another 30 minutes. Measurement of molded products,
The evaluation results are shown in Table 1.

[0059]

[Table 1]

The contents of the catalyst and nitrogen-containing organic base in Table 1 are as follows. HPTB: Cyclohexyltriphenylphosphonium tetraphenylborate (however, the content of alkali metal or alkaline earth metal components is Na <10 ppm, Mg <
10 ppm, Ca <10 ppm, K <10 ppm) PPTB: cyclopentyltriphenylphosphonium tetraphenylborate (however, the above metal component content is
Same as above. ) IPPB: isopropyltriphenylphosphonium tetraphenylborate (however, the above-mentioned metal component content is the same as the above.) PPPP: Cyclopentyltriphenylphosphonium phenolate (however, the above-mentioned metal component content is the same as above) HPPP: Cyclohexyltriphenylphosphonium phenolate (however, the content of the metal component is the same as above.) BTPH: Butyltriphenylphosphonium tetraphenylborate (however, the content of the metal component is the same as above) TPPH: Tetraphenylphosphonium Hydroxide TMAH: Tetramethylammonium hydroxide (however, the content of alkali metal or alkaline earth metal components is Na <1 ppb, Ca <1 ppb, K <1 pp
b)

[0061]

As described above, by carrying out the transesterification reaction using the catalyst according to the present invention, it becomes possible to efficiently produce a polycarbonate excellent in appearance (coloring) and hydrolysis resistance. This effect is considered to be based on the fact that the catalyst of the present invention has sufficient activity and can deactivate the catalyst at the final stage of the reaction.

Front page continuation (72) Inventor Koichi Suga Idemitsu Kosan Co., Ltd.

Claims (4)

[Claims] 1. A method for producing a polycarbonate, which comprises using a quaternary phosphonium salt containing a branched alkyl group as a reaction catalyst in producing a polycarbonate by a transesterification reaction. 2. The method for producing a polycarbonate according to claim 1, wherein the raw materials for the transesterification reaction are a dihydroxy compound and a carbonic acid diester. 3. The quaternary phosphonium salt containing a branched alkyl group is at least one selected from compounds represented by the general formula (I) and the general formula (II), respectively.
A method for producing the described polycarbonate. Embedded image [Here, n is an integer of 1 to 4. However, when n is plural, the branched alkyl groups may be the same as or different from each other. R ^{1 to} R ³ : at least one selected from hydrogen, an alkyl group, an alkyl group having a substituent, an aryl group and an aryl group having a substituent, and at least two of R ^{1 to} R ³ are bonded to form a ring. It may form a structure. However, this excludes the case where two are hydrogen at the same time. R ⁴ : an alkyl group, an alkyl group having a substituent,
An aryl group or an aryl group having a substituent. X: either OH, OR, BH ₄ , BR ₄ , RCOO, a halogen atom or HCO ₃ . Here, R is an alkyl group, an alkyl group having a substituent, an aryl group,
Alternatively, it is an aryl group having a substituent. Y: CO ₃ . ] 4. The method for producing a polycarbonate according to claim 1, wherein a nitrogen-containing organic base is used in combination with the reaction catalyst.