JP3283629B2 - Method for producing aromatic polycarbonate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing polycarbonate. More specifically, polymerization reaction rate, hue,
The present invention relates to a method for producing a polycarbonate having excellent heat resistance and the like.

[0002]

2. Description of the Related Art Polycarbonate is widely used because of its excellent mechanical properties such as impact resistance, heat resistance and transparency. As a method for producing such a polycarbonate, a method of directly reacting an aromatic dihydroxy compound such as bisphenol with phosgene (interface method), or a method in which an aromatic dihydroxy compound such as bisphenol and a diaryl carbonate such as diphenyl carbonate are melted. A method of transesterification (melting method) and the like are known.

Among such production methods, a method for producing a polycarbonate by a transesterification reaction between an aromatic dihydroxy compound and a diaryl carbonate will be described. This method uses a metal organic acid salt, an inorganic acid salt, or a catalyst as a catalyst. A method in which an aromatic dihydroxy compound and a diaryl carbonate are subjected to transesterification while being melted by heating, for example, finally to 250 to 330 ° C. under reduced pressure using an oxide, a hydroxide, a hydride or an alcoholate. is there.

This method has the advantage that polycarbonate can be produced at a lower cost than the above-mentioned interface method, but has the problem that the hue is unfavorable because the polymer is exposed to high temperatures for a long time. Was. Various catalysts have been proposed to improve such a hue, but are inferior to polycarbonates polymerized by the interface method and are not yet sufficient.

[0005]

Accordingly, an object of the present invention is to produce a polycarbonate having an excellent hue by a melt polymerization method using a highly active catalyst.

[0006]

Means for Solving the Problems In order to achieve the above object, the present inventors have studied diligently from the viewpoint that a system having a high polymerization reaction rate can produce a polycarbonate having a short heat history of a polymer and a good hue. As a result, the present inventors have found that polycarbonate produced by adding a specific aluminum compound to an alkali metal compound and / or an alkaline earth metal compound and performing melt polymerization has a high polymerization reaction rate and excellent hue. Reached.

That is, the present invention relates to (A) an alkali metal compound and / or an alkaline earth metal compound, and (B) an aluminum compound represented by the following formula (I).

[0008]

Embedded image Al (OR ₁ ) ₃ (I) wherein R ₁ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms. And (C) (i) a nitrogen-containing basic compound, (ii)
Aromatic polymerization, wherein an aromatic dihydroxy compound and a diaryl carbonate are melt-polymerized in the presence of a catalyst comprising at least one compound selected from the group consisting of a phosphorus-containing basic compound and (iii) a boric acid compound. This is a method for producing polycarbonate.

The aromatic dihydroxy compound that can be used in the present invention is not particularly limited, and examples thereof include a compound represented by the following formula (II).

[0010]

Embedded image

In the formula, X is

[0012]

Embedded image It is.

Here, R ₂ and R ₃ are the same or different,
It is a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 12 carbon atoms. As the hydrocarbon group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms is preferable. Examples of such an aliphatic hydrocarbon group include an alkyl group and an alkenyl group, and examples include a methyl group, an ethyl group, and a propyl group. Examples of the aromatic hydrocarbon group include a substituted or unsubstituted phenyl group and a naphthyl group. Examples of the halogen atom include chlorine, bromine and iodine.

R ₄ is a divalent hydrocarbon group having 4 to 20 carbon atoms, and examples thereof include an aliphatic hydrocarbon group such as an alkylene group and an alkenylene group, such as a butylene group and a pentylene group.

In the formula, R ₅ and R ₆ are the same or different and are a halogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples of the hydrocarbon group include an aliphatic hydrocarbon group having 1 to 12 carbon atoms and an aromatic group having 6 to 12 carbon atoms. Examples of the aliphatic hydrocarbon group include an alkyl group and an alkenyl group, and more specifically, a methyl group, an ethyl group, and a propyl group. Examples of the aromatic group include a substituted or unsubstituted phenyl group and a naphthyl group. Examples of the halogen atom include chlorine, bromine and iodine.

In the formula, m and n are the same or different and represent 0 or an integer of 1 to 4.

Specifically, the following compounds can be mentioned. Bis (4-hydroxyphenyl) methane,
1,1-bis (4-hydroxyphenyl) ethane, 2,
2-bis (4-hydroxyphenyl) propane, 2,2
-Bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4
-Hydroxy-3-methylphenyl) propane, 1,1
Bis (hydroxyaryl) alkanes such as -bis (4-hydroxy-t-butylphenyl) propane and 2,2-bis (4-hydroxy-3-bromophenyl) propane; 1,1-bis (4-hydroxyphenyl) ) Cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethylphenyl ether Dihydroxy aryl ethers such as
4,4'-dihydroxydiphenyl sulfide, 4,
Dihydroxydiaryl sulfides such as 4'-dihydroxy-3,3'-dimethyldiphenyl sulfide;
4,4'-dihydroxydiphenylsulfoxide, 4,
Dihydroxydiarylsulfoxides such as 4'-dihydroxy-3,3'-dimethyldiphenylsulfoxide;4,4'-dihydroxydiphenylsulfone;
Dihydroxydiaryl sulfones such as 4'-dihydroxy-3,3'-dimethyldiphenyl sulfone;
Dihydroxydiaryls such as 9-bis (4-hydroxyphenyl) fluorene;

Of these, in particular, 2,2-bis (4-
(Hydroxyphenyl) propane (bisphenol A) is preferably used. These aromatic dihydroxy compounds can be used alone or in combination.

Diaryl carbonate has 6 to 2 carbon atoms.
The carbonate is not particularly limited as long as it has a zero-substituted aryl group. Specifically, diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (Diphenyl) carbonate and the like can be mentioned. Of these, diphenyl carbonate is particularly preferably used. These diaryl carbonates can be used alone or in combination. The above diaryl carbonate is used in an amount of usually 1.0 to 1.30 mol, preferably 1.01 to 1.20, per mol of the aromatic dihydroxy compound.
Desirably, they are used in molar amounts.

The alkali metal compound and alkaline earth metal compound used in the present invention include hydroxides, hydrogen carbonates, carbonates, acetates, borohydrides, stearates, benzoates and bisphenols. And salt.

Specific examples of the alkali metal compound include sodium hydroxide, lithium hydroxide, potassium hydroxide,
Sodium bicarbonate, lithium bicarbonate, potassium bicarbonate, sodium carbonate, lithium carbonate, potassium carbonate,
Sodium acetate, lithium acetate, potassium acetate, sodium borohydride, lithium borohydride, potassium borohydride, sodium stearate, lithium stearate, potassium stearate, sodium benzoate,
Examples thereof include lithium benzoate, potassium acid mineral, disodium salt of bisphenol A, dilithium salt, dipotassium salt, phenol sodium salt, lithium salt and potassium salt.

Further, as the alkaline earth metal compound,
Specifically, calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate,
Examples thereof include magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, magnesium stearate, and strontium stearate.

These compounds can be used alone or in combination. Such an alkali metal compound and / or alkaline earth metal compound is used in an amount of 10 ^-8 to 10 ^-1 mol, preferably 10 ^-7 to 10 ^-2 mol, per 1 mol of the aromatic dihydroxy compound. .

The aluminum compound (B) has the following formula (I)

[0025]

Embedded image A compound represented by the formula: Al (OR ₁ ) ₃ (I) Here, R ₁ has 1 to 2 carbon atoms.
Represents a monovalent hydrocarbon group up to 0, and has 1 to 12 carbon atoms;
A monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group having 5 to 12 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms are preferable. Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, a propyl group, an alkyl group such as a propenyl group, an alkenyl group, and the like.As the alicyclic hydrocarbon group,
Examples thereof include cycloalkyl groups such as cyclopentyl group and cyclohexyl group, and examples of the aromatic group include phenyl group and naphthyl group which may be substituted.

More specifically, the following compounds can be mentioned. Trimethoxyaluminum, triethoxyaluminum, triisopropoxyaluminum, tri-n-butyroxyaluminum, tri-sec-butyroxyaluminum, tri-t-butyroxyaluminum, trihexyloxyaluminum, trioctyloxyaluminum, tricyclohexyloxy aluminum,
Examples include aluminum triphenoxy, aluminum trinaphthyloxy, aluminum tris (chlorophenoxy), and aluminum tris (diphenyloxy). These compounds can be used alone or in combination. One mole of the aromatic dihydroxy compound can be used in one mole.
It is used in an amount of 0 ^-8 to 10 ^-1 mol, preferably 10 ^-7 to 10 ^-2 mol.

In the present invention, at least one compound selected from the group consisting of (i) a nitrogen-containing basic compound, (ii) a phosphorus-containing basic compound and (iii) a boric acid compound is used together with the above-mentioned compounds.

As the nitrogen-containing basic compound, for example, a nitrogen-containing compound which is easily decomposed or volatile at a high temperature, specifically, tetramethylammonium hydroxide (Me ₄ N
OH), tetraethylammonium hydroxide (Et
₄ NOH), tetrabutylammonium hydroxide alkyl, aryl, ammonium hydroxide oxides having like Aruariru group such as (Bu ₄ NOH), trimethylbenzylammonium hydroxide (phenyl _{-CH 2 (Me) 3 NOH)} , trimethylamine, triethylamine , Tertiary amines such as dimethylbenzylamine and triphenylamine, secondary amines represented by R ₂ NH (where R is an alkyl group such as methyl and ethyl, and an aryl group such as phenyl and toluyl); RN
Primary amines represented by H ₂ (wherein R is the same as described above), imidazoles such as 2-methylimidazole, 2-phenylimidazole, or ammonia, tetramethylammonium borohydride (Me ₄ NB)
H ₄ ), tetrabutylammonium borohydride (Bu ₄ NBH ₄ ), tetrabutylammonium tetraphenylborate (Bu ₄ NBPh ₄ ), tetramethylammonium tetraphenylborate (Me ₄ NBPh)
Basic salts such as ₄ ) are used. Of these,
Tetraalkylammonium hydroxides, in particular, tetraalkylammonium hydroxides for electronic use with little metal impurities are preferred.

Examples of the boric acid compound include boric acid and boric acid esters. As the borate ester, a general formula

[0030]

A borane represented by B (OR) _n (OH) _{3-n wherein} R is alkyl such as methyl or ethyl, aryl such as phenyl, and n is 1, 2 or 3. Acid esters are used.

Specific examples of such borate esters include trimethyl borate, triethyl borate, tributyl borate, trihexyl borate, triheptyl borate, triphenyl borate, tritolyl borate, and trinaphthyl borate. Is used.

In the present invention, a phosphorus-containing basic compound is used as a co-catalyst. As such a compound, for example, a phosphonium compound is used. Specifically, tetraphenylphosphonium hydroxide, tetranaphthylphosphonium hydroxide, tetra (chlorophenyl) phosphonium hydroxide, tetra (biphenyl) phosphonium hydroxide, tetratolylphosphonium hydroxide, and tetraarylphosphonium hydroxide having another substituted aryl group , Tetramethylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetrabutylphosphonium hydroxide, tetraalkylphosphonium hydroxide having another substituted alkyl group, and the like.

In the present invention, the method of charging the catalyst may be either solid or liquid, but is preferably a solution or suspension. The concentration of the solution or suspension may be a concentration that can be handled in a liquid state, and is preferably 30% by weight or less, more preferably 20% by weight or less. The concentration of oxygen dissolved in the solution or suspension is preferably 100 ppm or less, more preferably 50 ppm or less, even more preferably 10 ppm or less. If it exceeds this range, coloring or branched components are likely to be generated due to the influence of dissolved oxygen.

In the present invention, it is also preferable to add various stabilizers in a molten state at least one time before, during or after the polymerization. Examples of the stabilizer include an ion-containing acidic compound and / or a derivative formed from the acidic compound, a phenol-based stabilizer, a thioether-based stabilizer, a phosphorus-based stabilizer, a hindered amine-based stabilizer, an epoxy compound, and a salicylic acid-based ultraviolet absorber. Agents, benzotriazole-based ultraviolet absorbers, and the like.

Examples of the ion-containing acidic compound and / or a derivative formed from the acidic compound include sulfurous acid, sulfuric acid, sulfinic acid compounds, sulfonic acid compounds, and derivatives thereof. Specifically, as the sulfuric acid derivatives, dimethyl sulfate, diethyl sulfate, sulfuric acid,
Examples thereof include dipropyl sulfate, dibutyl sulfate, diphenyl sulfate, dimethyl sulfite, diethyl sulfite, and diphenyl sulfite.

Examples of the sulfinic acid compound include benzenesulfinic acid, toluenesulfinic acid, and naphthalenesulfinic acid. Examples of the sulfonic acid compound and its derivative include the following compounds. That is, benzenesulfonic acid, p
-Sulfonic acids such as toluenesulfonic acid, methyl benzenesulfonate, ethyl benzenesulfonate, butyl benzenesulfonate, octyl benzenesulfonate, phenyl benzenesulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, p- Butyl toluenesulfonate, octyl p-toluenesulfonate, p-
Examples include sulfonic acid esters such as phenyl toluenesulfonic acid and ammonium sulfonic acid salts such as ammonium p-toluenesulfonic acid.

These compounds can be used alone or in combination. Of these, [B] pK
As the sulfur-containing acidic compound having an a value of 3 or less and a derivative formed from the acidic compound, a sulfonic acid compound or a derivative thereof is preferably used. In particular, benzenesulfonic acid, butylbenzenesulfonic acid, p-toluenesulfonic acid, Ethyl p-toluenesulfonate and butyl p-toluenesulfonate are preferably used.

Examples of the phenolic stabilizer include, for example, n
-Octadecyl-3- (4-hydroxy-3 ', 5'-
Di-tert-butylphenyl) propionate, tetrakis [methylene-3- (3 ', 5'-di-tert-butyl-4-)
Hydroxyphenyl) propionate] methane, 1,
1,3-Tris (2-methyl-4-hydroxy-5-t
-Butylphenyl) butane, distearyl (4-hydroxy-3-methyl-5-tert-butyl) benzylmalonate, 4-hydroxymethyl-2,6-di-tert-butylphenol, etc., which are used alone They may be used alone or in combination of two or more.

As the thioether-based stabilizer, for example,
Dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl-3,3'-thiodipropionate, ditridecyl-3,3'-thiodipropionate, pentaerythritol-tetrakis- (β
-Lauryl-thiopropionate) and the like, and these may be used alone or as a mixture of two or more.

Examples of the phosphorus-based stabilizer include bis (2,4-di-t-butylphenyl) pentaerythrityl diphosphite, diphenyldecyl phosphite, and the like.
Arylalkyl phosphites such as phenylisooctyl phosphite and 2-ethylhexyldiphenyl phosphite; trimethyl phosphite, triethyl phosphite, tributyl phosphite, trioctadecyl phosphite, distearyl pentaerythrityl diphosphite, and tris (2-chloroethyl ) Trialkyl phosphites such as phosphite and tris (2,3-dichloropropyl) phosphite; tricycloalkyl phosphites such as tricyclohexyl phosphite; triphenyl phosphite, tricresyl phosphite, tris (ethylphenyl) Phosphite, tris (2,4-di-t
Tributyl phosphite, tris (hydroxyphenyl) phosphite, and other triaryl phosphites; trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctadecyl phosphate, distearyl pentaerythrityl phosphate, tris (2-chloroethyl) phosphate, etc. Trialkyl phosphates such as tricyclohexyl phosphate; triaryl phosphates such as triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate and 2-ethylphenyl diphenyl phosphate; They may be used alone or in combination of two or more.

The hindered amine stabilizers include
For example, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, 8-benzyl-7,7,9,9
-Tetramethyl-3-octyl-1,2,3-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, tetrakis (2,2 , 6,6-tetramethyl-4
—Piperidyl) 1,2,3,4-butanetetracarboxylate and the like, and these may be used alone or as a mixture of two or more.

In the present invention, a compound having one or more epoxy groups in one molecule is used as the epoxy compound.

Specific examples of such an epoxy compound include epoxidized soybean oil, epoxidized linseed oil, phenylglycidyl ether, t-butylphenylglycidyl ether, 3,4-epoxycyclohexylmethyl-
3 ', 4'-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylethylene oxide, cyclohexylmethyl-3,4-epoxycyclohexylcarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6'-methylsilohexylcarboxy Diglycidyl ester of phthalic acid, diglycidyl ester of phthalic acid, diglycidyl ester of hexahydrophthalic acid, bis-epoxydicyclopentadienyl ether, bis-epoxyethylene glycol, bis-epoxycyclohexyl adipate, butadiene Epoxide, tetraphenylethylene epoxide, octyl epoxy tartrate, epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane, 3,5- Methyl-1,2-epoxycyclohexane, 3-methyl -5-t-butyl-1,2
Epoxycyclohexane, octadecyl-2,2-dimethyl-3,4-epoxycyclohexylcarboxylate, N-butyl-2,2-dimethyl-3,4-epoxycyclohexylcarboxylate, cyclohexyl-2
-Methyl-3,4-epoxycyclohexylcarboxylate, N-butyl-2-isopropyl-3,4-epoxy-5-methylcyclohexylcarboxylate, octadecyl-3,4-epoxycyclohexylcarboxylate, 2-ethylhexyl-3 '4,4'-Epoxycyclohexylcarboxylate, 4,6-dimethyl-
2,3-epoxycyclohexyl-3 ', 4'-epoxycyclohexylcarboxylate, 4,5-epoxytetrahydrophthalic anhydride, 3-tert-butyl-4,5-
Epoxy tetrahydrophthalic anhydride, diethyl-4,5
-Epoxy-cis-1,2-cyclohexyldicarboxylate, di-n-butyl-3-tert-butyl-4,5-
Epoxy-cis-1,2-cyclohexyldicarboxylate and the like can be mentioned.

Examples of the salicylic acid-based ultraviolet absorber include phenyl salicylate and pt-butylphenyl salicylate. As the benzophenone-based ultraviolet absorber, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone,
2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-2'-
Carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2-
Hydroxy-4-n-octoxybenzophenone, 2,
2 ', 4,4'-tetrahydroxybenzophenone, 4
-Dodecyloxy-2-hydroxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, and the like.

As the benzotriazole-based ultraviolet absorber, 2- (2'-hydroxy-5'-methyl-phenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-di-t-butyl-phenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-
5'-methyl-phenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-
Butyl-phenyl) -5-chlorobenzotriazole,
2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-di-t-amylphenyl) benzotriazole, 2- [2'-hydroxy-3'-(3 ", 4",
5 ", 6" -tetrahydrophthalimidomethyl) -5 '
-Methylphenyl] benzotriazole, 2,2'-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] and the like. .

Examples of the cyanoacrylate-based ultraviolet absorber include 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, ethyl-2-cyano-3,3-diphenyl acrylate and the like.

These compounds are used in an amount of 10 ^-8 to 10 ^-1 mol, preferably 10 ^-7 to 10 ^-2 mol, per 1 mol of the aromatic dihydroxy compound.

In the present invention, when the aromatic dihydroxy compound and the diaryl carbonate are melt-polycondensed to produce a polycarbonate, the reaction system has 10 to 40, preferably 15 to 40, carbon atoms as a terminal blocking agent.
Forty phenols are present in an amount of 0.05 to 10 mol%, preferably 0.5 to 7 mol%, more preferably 1 to 5 mol%, based on the aromatic organic dihydroxy compound.

As the phenols having 10 to 40 carbon atoms as described above, the following compounds are used. o-
m-butylphenol, p-cyclohexylphenol, o-phenylphenol, m-isobutylphenol, mn-nonylphenol, pt-butylphenol, om-pentylphenol, p-cumylphenol, pm-pentylphenol , O-naphthylphenol, pn-pentylphenol, mn-hexylphenol, 2,6-di-tert-butylphenol,
2,4-di-tert-butylphenol, 3,5-di-tert-
Butylphenol, 2,6-dicumylphenol, 3,
5-Dicumylphenol, 2,2,2-trimethyl-4
Monovalent phenols such as monohydroxychroman derivatives such as-(hydroxyphenyl) chroman are used.

The catalysts used in the above-mentioned amounts are preferably used because the polycondensation reaction can proceed at a sufficient rate and a high-molecular-weight polycarbonate can be produced with high polymerization activity.

In the presence of such a catalyst, the polycondensation reaction between the aromatic dihydroxy compound and the diaryl carbonate can be carried out under the same conditions as conventionally known polycondensation reaction conditions.

Specifically, the first-stage reaction was carried out at 80 to 25
0 ° C., preferably 100-230 ° C., more preferably 120-190 ° C., for 0-5 hours, preferably 0 ° C.
The aromatic dihydroxy compound and the diaryl carbonate are reacted under reduced pressure for 4 to 4 hours, more preferably 0 to 3 hours. Next, the reaction temperature is increased while increasing the degree of vacuum of the reaction system, and the reaction between the aromatic dihydroxy compound and the diaryl carbonate is carried out. Finally, the reaction is carried out under a reduced pressure of 5 mmHg or less, preferably 1 mmHg or less, at a pressure of 240 to 3 mmHg.
A polycondensation reaction between the aromatic dihydroxy compound and the diaryl carbonate is performed at 20 ° C.

The above-mentioned polycondensation reaction may be carried out continuously or batchwise. The reaction apparatus used for performing the above reaction may be a tank type, a tube type, or a tower type.

The reaction product polycarbonate obtained as described above usually has an intrinsic viscosity (phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 40/60)) measured at 35 ° C. ) Is 0.1-1.
0, preferably 0.2 to 0.8.

In the present invention, the polycarbonate obtained as described above has ordinary heat stability, an ultraviolet absorber, a releasing agent, a colorant, an antistatic agent, a lubricant, an antifogging agent as long as the object of the present invention is not impaired. , Natural oils, synthetic oils, waxes, organic fillers, inorganic fillers and the like.

[0056]

According to the present invention, the polymerization reaction rate is high, and as a result, a polycarbonate having an excellent hue can be efficiently produced.

[0057]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

In the present specification, the intrinsic viscosity is phenol /
The measurement was performed with a 1,1,2,2-tetrachloroethane mixed solvent (weight ratio 40/60). The hue was observed by visual observation of the polymerized pellet.

[0059]

EXAMPLES 1-5, COMPARATIVE EXAMPLES 1-4 A predetermined amount of bisphenol A, diphenyl carbonate and a catalyst shown in Tables 1 and 2 were mixed with a stirring device and a distilling tube.
into a 3 ml stainless steel flask and purge with degassed nitrogen.
After performing the reaction twice, the mixture was dissolved at 180 ° C. Next, while maintaining this temperature, the pressure was reduced to 30 mmHg, and the reaction proceeded for 45 minutes, and further reduced to 15 mmHg for 30 minutes. The conversion was determined from the amount of phenol distilled out during the initial polymerization reaction, and is shown in Tables 1 and 2. Next, the temperature was raised to 290 ° C. over 45 minutes, and finally 290 ° C., 1 mm
The late-stage polymerization reaction was carried out at a pressure of not more than Hg for the time shown in Tables 1 and 2. Tables 1 and 2 show the observation results of intrinsic viscosity and hue of the obtained polycarbonate.

For comparison, the results when only the alkali metal compound or the alkaline earth metal compound was used as a catalyst are shown in Tables 1 and 2. The results show that the catalyst system of the present invention has a high activity and a good hue. It can be seen that can be manufactured.

[0061]

[Table 1]

[0062]

[Table 2]

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Katsushi Sasaki 2-1 Hinode-cho, Iwakuni-shi, Yamaguchi Prefecture Teijin Limited Iwakuni Research Center (56) References JP-A-4-36346 (JP, A) Hei 2-124934 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 64/00-64/42

Claims (1)

(57) [Claims] (A) an alkali metal compound and / or an alkaline earth metal compound; and (B) an aluminum compound represented by the following formula (I): ## STR1 ## wherein, Al (OR ₁ ) ₃ . , R ₁ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms. And (C) (i) a nitrogen-containing basic compound, (ii)
Aromatic polymerization, wherein an aromatic dihydroxy compound and a diaryl carbonate are melt-polymerized in the presence of a catalyst comprising at least one compound selected from the group consisting of a phosphorus-containing basic compound and (iii) a boric acid compound. Method for producing polycarbonate.