JPH0952947A - Production of aromatic polycarbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically obtain an aromatic polycarbonate excellent in hue. SOLUTION: This aromatic polycarbonate is obtained by polycondensation between an aromatic dihydroxy compound and a carbonic diester in a molten state under heating. In this case, the molten mixture of these components at the weight ratio of (1:1) exhibits a Hazen unit of <=20 at 175 deg.C in the atmosphere and <=40 five hours after held at 175 deg.C in the atmosphere.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aromatic polycarbonate, and more particularly to a method for producing an aromatic polycarbonate having a good color tone.

[0002]

2. Description of the Related Art Polycarbonate resins obtained by interfacial polycondensation of bisphenol A and phosgene are widely used for various purposes due to their excellent mechanical properties and thermal properties, but use of toxic phosgene However, there are many problems such as environmental damage due to the use of methylene chloride as a solvent. Therefore, recently, the transesterification method which does not use methylene chloride or phosgene has been in the limelight, but the polycarbonate resin obtained by the transesterification method usually undergoes polycondensation while being heated to a temperature of 250 to 330 ° C., so that it is carried out at a high temperature for a long time. The polycarbonate obtained by the above method could not be used in the field where the color tone is required, because the quality history such as the deterioration of the color tone due to the heat history of 1. was not obtained.

Therefore, various methods have recently been shown for providing a polycarbonate having an excellent color tone. For example
In Japanese Patent No. 18868, it is proposed that the color tone of the polycarbonate is improved by making the hydrolyzable chlorine contained in the carbonic acid diester 3 ppm or less, sodium ion 1 ppm or less, and iron ion 1 ppm or less. However, it is not sufficient to produce a polycarbonate having an excellent hue simply by using a carbonic acid diester in which the chlorine content, sodium ion, and iron ion of the carbonic acid diester are below the above specified values. This is because the other trace impurities of the carbonic acid diester and the trace impurities of the aromatic dihydroxy compound used mutually deteriorate the carbonic acid diester and the aromatic dihydroxy compound, which greatly contribute to the deterioration of the hue of the polycarbonate.

However, these trace impurities are difficult to be qualitatively and quantitatively analyzed by the current analytical technique, and there is a big problem that a carbonic acid diester and an aromatic dihydroxy compound which give a polycarbonate having an excellent color tone by a transesterification method cannot be defined by a usual analytical technique. there were.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a polycarbonate by the transesterification method, which is inexpensive to produce and is excellent in color tone.

The present inventor has found that the molten Hazen color number at a specific temperature in a mixed state of a carbonic acid diester and an aromatic dihydroxy compound is a specific value or less, and the molten Hazen color number after holding for a specific time is a specific value or less. They have found that it is effective to use a carbonic acid diester and an aromatic dihydroxy compound, and have completed the present invention.

[0007]

That is, according to the present invention, when an aromatic polycarbonate is produced by subjecting an aromatic dihydroxy compound and a carbonic acid diester to polycondensation under heating and melting, an aromatic polycarbonate is produced with a 1: 1 ratio of the aromatic dihydroxy compound and the carbonic acid diester. An aromatic dihydroxy compound and a carbonic acid diester having a melted Hazen color number of 20 parts or less at 175 ° C. in the atmosphere and a melted Hazen color number of 40 or less after being kept at 175 ° C. for 5 hours in the air. Is used to produce an aromatic polycarbonate.

In the present invention, when an aromatic polycarbonate is produced by polycondensing an aromatic dihydroxy compound and a carbonic acid diester under heating and melting to produce an aromatic polycarbonate, a 1: 1 part by weight mixture of the aromatic dihydroxy compound and the carbonic acid diester is heated to 175 ° C. in the atmosphere. The number of molten Hazen colors is 20 or less, preferably 15 or less, more preferably 10 or less,
Further, it is characterized in that it has a molten Hazen color number of 40 or less, preferably 30 or less after being kept in the atmosphere at 175 ° C. for 5 hours.

In the present invention, the fused Hazen color number is J
1 of carbonic acid diester and aromatic dihydroxy compound as measured by the method described in IS K-4101.
After 1 part by weight of the mixture is completely melted at a specific temperature, the melt Hazen color number when the solution reaches the specific temperature is measured. The solution has reached a specific temperature and is measured by the molten Hazen color number after the specific temperature is maintained.

If the melt Hazen color number of the mixture at 175 ° C. exceeds 20, the color tone of the obtained polycarbonate is deteriorated, which is not preferable, and even if the melt Hazen color number at 175 ° C. is 20 or less, it is 5 hours at 175 ° C. If the number of molten Hazen colors after holding in air exceeds 40, the color tone of the obtained polycarbonate is deteriorated, which is not preferable. Even if the number of molten Hazen colors after holding in air at 175 ° C. for 5 hours is 40 or less, molten Hazen at 175 ° C. When the number of colors exceeds 20, the color tone of the obtained polycarbonate deteriorates, which is not preferable.

In order to produce such a mixture of an aromatic dihydroxy compound and a carbonic acid diester having a melt Hazen color number of a specific value or less, the carbonic acid diester is prepared by the phosgene method as a phenyl chloroformate or water as an intermediate. Impurities such as salts and metal salts that are soluble in are preferably removed by washing with hot water or a weakly basic aqueous solution in a molten state in the molten state as shown in Polycarbonate Resin P62 by Nikkan Kogyo Shimbun. It is preferable that after the above-mentioned purification step, is further distilled under reduced pressure. The carbonic acid diester after washing with hot water may be distilled under reduced pressure as it is, but a basic substance such as an alkali metal salt or an alkaline earth metal salt or a hydroxide may be added to the carbonic acid diester at 10 ^-10 to 10 ^-1. Molar, preferably 10 ⁻⁸ to 10 ⁻³ mol may be added and distilled under reduced pressure.

As the basic substance, solid or aqueous solution such as sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate can be used. Further, when using an aromatic carbonic acid diester obtained by, for example, a transesterification reaction of a dialkyl carbonate and a phenol, which does not depend on the phosgene method, in some cases, only the vacuum distillation may bring the melted Hazen color number to a characteristic value or less. You can It can also be purified by recrystallization using an aromatic or aliphatic organic solvent.

As described above, also for the aromatic dihydroxy compound, the melting Hazen color number shown in the present invention can be achieved by the above-mentioned purification methods and by combining them.

The aromatic dihydroxy compound used in the present invention is not particularly limited, but for example, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2 2-bis (4
-Hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-t-butylphenyl) propane, etc. Bis (hydroxyaryl) alkanes, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1
-Bis (hydroxyaryl) cycloalkanes such as bis (hydroxyphenyl) cyclohexane, 4,4 '
-Dihydroxyaryl ethers such as dihydroxydiphenyl ether, dihydroxyaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, dihydroxyaryl sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-
Dihydroxyaryl sulfones such as dihydroxydiphenyl sulfone are used. 2,2-bis (4-hydroxyphenyl) propane is particularly preferable.

As the carbonic acid diester used in the present invention, an optionally substituted aryl group having 6 to 10 carbon atoms,
Esters such as aralkyl groups can be mentioned. Specifically, diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl)
Carbonate etc. are mentioned.

In producing the polycarbonate according to the present invention, 1.00 to 1.30 mol, preferably 1.005 to 1.10 mol, per 1 mol of the aromatic carbonic acid diester aromatic dihydroxy compound as described above. Used in quantity.

In the present invention, a polymerization catalyst can be used to accelerate the polymerization rate when producing a polycarbonate by the transesterification reaction between the aromatic dihydroxy compound and the aromatic carbonic acid diester as described above.

Such a polymerization catalyst is composed of an alkali metal compound and an alkaline earth metal compound as main components, and a nitrogen-containing basic compound as a secondary component, if necessary.

As the alkali metal compound, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, potassium acetate, lithium acetate , Sodium stearate, potassium stearate, lithium stearate, sodium salt of bisphenol A, potassium salt, lithium salt, sodium benzoate, potassium benzoate, lithium benzoate and the like.

Examples of the alkaline earth metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate and carbonic acid. Examples thereof include magnesium, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate.

Examples of the nitrogen-containing basic compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylamine, triethylamine, dimethylbenzylamine, triphenylamine and the like.

The above polymerization catalysts may be used alone or in combination.

The amount of these polymerization catalysts used in the present invention is 1 × 10 ⁻⁷ per 1 mol of the aromatic dihydroxy compound in the case of alkali metal compounds and alkaline earth metal compounds.
１1 × 10 ^-4 equivalents, preferably 1 × 10 ^{-6 to} 5 × 10 ^-5
It is selected within the range of equivalents. When a nitrogen-containing basic compound is used as a secondary component, the aromatic dihydroxy compound 1
1 × 10 ⁻⁵ to 1 × 10 ⁻³ equivalent, preferably 1
× selected at 10 ^-5 to 5 × 10 ^-4 equivalent weight in the range.

Alkali metal compounds and alkaline earth metals
Compounds and nitrogen-containing basic compounds are used in combination
In this case, the preferred amount used corresponds to the sum of the above ranges,
1 × 10 to 1 mol of dihydroxy compound^-7~ 1 × 10
^-FourEquivalent, preferably 1 × 10 ^-6~ 5 × 10^-FiveEquivalent is selected
It is.

In the present invention, other compounds may be used as a co-catalyst if necessary. Examples of such compounds include alkali metal and alkaline earth metal salts of hydroxides of boron and aluminum, quaternary ammonium salts, alkoxides of alkali metals and alkaline earth metals, organic metals of alkali metals and alkaline earth metals. Suitable for general esterification and transesterification of acid salts, zinc compounds, boron compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, osmium compounds, antimony compounds, zirconium compounds, etc. The catalyst used may be, but is not limited to. When using a co-catalyst, only 1 type may be used and 2 or more types may be used in combination.

In the transesterification reaction between the aromatic dihydroxy compound and the aromatic carbonic acid diester of the present invention, the aromatic monohydroxy compound produced by stirring with heating under an inert gas atmosphere is distilled as is conventionally known. It is done by letting out. The reaction temperature is usually in the range of 120 to 350 ° C., and the system decompression degree is 10 to 0.1 Torr in the latter stage of the reaction.
The reaction is completed by facilitating the distillation of the aromatic monohydroxy compound produced by increasing the ratio to r.

Stabilizers may be used in the present invention.

The method of adding the stabilizer to the polycondensation product is not particularly limited. For example, these may be added while the reaction product polycarbonate is in a molten state, or may be added after re-melting after pelletizing the polycarbonate once. In the former case, these may be added while the polycarbonate, which is the reaction product in the molten state or the reaction product in the extruder obtained after the completion of the polycondensation reaction, is in the molten state. It is also possible to add a stabilizer and knead while the polycarbonate obtained from the reaction is pelletized from the reactor through the extruder. Each stabilizer will be described below.

Stabilizers of formula (I)

[0030]

Embedded image

Here, A ¹ is an m-valent hydrocarbon group which may have a substituent, Y ¹ is a single bond or an oxygen atom, and X ¹ is a secondary or tertiary monovalent hydrocarbon group. Hydrocarbon groups, 1
An equivalent amount of a metal cation, an ammonium cation or a phosphonium cation, and m is an integer of 1 to 4. However, when Y ¹ is a single bond, all of m X ¹ are not one equivalent of metal cation.

As the m-valent hydrocarbon group, for example, a m-valent saturated aliphatic hydrocarbon group, an aromatic hydrocarbon group, a saturated aliphatic-aromatic hydrocarbon group and the like can be mentioned as preferable ones.

Y ¹ is a single bond or an oxygen atom, and X ¹ is a secondary or tertiary monovalent hydrocarbon group, 1 equivalent of a metal cation, an ammonium cation or a phosphonium cation.

Examples of the secondary or tertiary monovalent hydrocarbon group include, for example, the following formula (I) -d.

[0035]

Embedded image

[Where R^FifteenIs hydrogen atom or carbon number
1 to 5 alkyl groups;¹⁶Is a hydrogen atom, phenyl
A group or an alkyl group having 1 to 5 carbon atoms, and R
¹⁷Is R ^FifteenSame as or different from R^FifteenIs the same as
You. ] A secondary or tertiary alkyl group represented by
New Of these, especially R^FifteenAnd R¹⁷Are the same
Is different from hydrogen atom, methyl group, ethyl group or propene
Is a radical and R¹⁶Is a methyl group or a phenyl group
More preferably.

One equivalent metal cation is, for example, an alkali metal cation such as lithium, sodium or potassium; 1/2 of an alkaline earth metal cation such as calcium or barium, or 1/3 of a trivalent metal cation such as aluminum. Etc. can be mentioned.

As the ammonium cation, for example, the following formula (I) -a is used.

[0039]

Embedded image

[Where R ¹ , R ² , R ³ and R
⁴ are each independently a hydrogen atom or a monovalent hydrocarbon group. And a cation represented by the formula:

In the formula (I) -a, ¹ represented by R ¹ or the like
Examples of the valent hydrocarbon group include an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, and 7 to 10 carbon atoms.
The aralkyl group and the like are preferable.

The phosphonium cation is, for example, the following formula (I) -b

[0043]

Embedded image

[Where R ⁵ , R ⁶ , R ⁷ and R
⁸ are hydrogen atoms or monovalent hydrocarbon groups which are independent of each other. And a cation represented by the formula:

In the formula (I) -b, 1 represented by R ^{5 and the} like
As the valent hydrocarbon group, the same monovalent carbon group as exemplified for the formula (I) -a can be mentioned.

Of these, X ¹ is secondary or tertiary.
Grade alkyl group, alkali metal cation, the above formula (I)
The cation represented by -a and the cation represented by the above formula (I) -b are preferable.

In the above formula (I), m is an integer of 1 to 4, preferably 1 or 2.

The compound represented by the above formula (I) is Y ¹
It is divided into two groups for convenience according to the definition of. That is,
A compound group in which Y ¹ is a single bond and a compound group in which Y ¹ is an oxygen atom. A compound group in which Y ¹ is a single bond has the following formula (I) -1 when, for example, m is 1.

[0049]

Embedded image A ¹ —SO ₃ X ¹ (I) -1 [wherein the definitions of A ¹ and X ¹ are the same as those in the above formula (I). ]] Is represented.

Among the compounds represented by the above formula (I) -1, it is preferable that A ¹ is a monovalent saturated aliphatic hydrocarbon group or a saturated aliphatic-aromatic hydrocarbon group, and especially the following formula (I) ) -C

[0051]

[Chemical 6]

[Here, A ¹¹ is an alkyl group having 1 to 18 carbon atoms, and j is an integer of 0 or 1. Is particularly preferably a group represented by

Compounds in which Y ¹ is an oxygen atom are
For example, when m is 1, the following formula (I) -2

[0054]

Embedded image A ¹ —O—SO ₃ X ¹ (I) -2 [wherein, the definitions of A ¹ and X ¹ are the same as those in the above formula (I). ]] Is represented.

Among the compounds represented by the above formula (I) -2, A ¹ is preferably a monovalent saturated aliphatic hydrocarbon group, and particularly preferably an alkyl group having 1 to 18 carbon atoms. .

Specific examples of the compound represented by the above formula (I) include the following compounds.

Y ¹ is a single bond and X ¹ is secondary or tertiary.
When the compound is a primary monovalent hydrocarbon group and m is 1, benzylbenzenesulfonate, 2-phenyl-2-propylbenzenesulfonate, 2-phenyl-2-butylbenzenesulfonate, toluenesulfone Acid benzyl, 2-phenyl-2-propyl toluenesulfonate, 2-propyl-2-butyl toluenesulfonate,
Benzyl octylbenzenesulfonate, 2-phenyl-2-propyl octylbenzenesulfonate, 2-phenyl-2-butyl octylbenzenesulfonate, benzyl dodecylbenzenesulfonate, 2-phenyl-2-propyl dodecylbenzenesulfonate, dodecylbenzene 2-phenyl-2-butyl sulfonate and the like can be mentioned.

Y ¹ is a single bond, and X ¹ is the above formula (I).
A phosphonium cation represented by -b and m
Wherein the compound is 1, hexylsulfonic acid tetramethylphosphonium salt, hexylsulfonic acid tetraethylphosphonium salt, hexylsulfonic acid tetrabutylphosphonium salt, hexylsulfonic acid tetrahexylphosphonium salt, hexylsulfonic acid tetraoctylphosphonium salt, octylsulfone Acid tetramethylphosphonium salt, octylsulfonic acid tetraethylphosphonium salt, octylsulfonic acid tetrabutylphosphonium salt, octylsulfonic acid tetrahexylphosphonium salt, octylsulfonic acid tetraoctylphosphonium salt, decylsulfonic acid tetramethylphosphonium salt, decylsulfonic acid tetraethylphosphonium salt Salt, tetrabutyl phosphonium decyl sulfonate, tetrahexyl phospho decyl sulfonate Umium salt, tetraoctylphosphonium decylsulfonate, tetramethylphosphonium dodecylsulfonate, tetraethylphosphonium dodecylsulfonate, tetrabutylphosphonium dodecylsulfonate, tetrahexylphosphonium dodecylsulfonate, tetraoctylphosphonium dodecylsulfonate, Hexadecylsulfonic acid tetramethylphosphonium salt, hexadecylsulfonic acid tetraethylphosphonium salt, hexadecylsulfonic acid tetrabutylphosphonium salt, hexadecylsulfonic acid tetrahexylphosphonium salt, hexadecylsulfonic acid tetraoctylphosphonium salt, benzenesulfonic acid tetramethylphosphonium Salt, benzenesulfonic acid tetraethylphosphonium salt, benzenesulfonic acid tetrabutyl Suhoniumu salts, benzenesulfonic acid tetrahexyl phosphonium salts, benzenesulfonic acid tetraoctyl phosphonium salts, tetramethyl phosphonium salt toluenesulfonic acid,
Toluenesulfonic acid tetraethylphosphonium salt, toluenesulfonic acid tetrabutylphosphonium salt, toluenesulfonic acid tetrahexylphosphonium salt, toluenesulfonic acid tetraoctylphosphonium salt, dodecylbenzenesulfonic acid tetramethylphosphonium salt, dodecylbenzenesulfonic acid tetraethylphosphonium salt, dodecylbenzene Sulfonic acid tetrabutylphosphonium salt,
Examples thereof include dodecylbenzenesulfonic acid tetrahexylphosphonium salt and dodecylbenzenesulfonic acid tetraoctylphosphonium salt.

When Y ¹ is an oxygen atom, X ¹ is a secondary or tertiary monovalent hydrocarbon group, and m is 1, the compound has a total carbon number of A ¹ and X ^1. Is 8 ~
It is preferably 40. Specific examples thereof include dibutyl sulphate, dipentyl sulphate, dihexyl sulphate, dioctyl sulphate, dinonyl sulphate, didecyl sulphate, ditridecyl sulphate, ditetradecyl sulphate, dihexadecyl sulphate, dicyclohexyl sulphate and dibenzyl sulphate. It is to be understood that all of the alkyl groups in these embodiments are secondary or tertiary.

Compounds in which Y ¹ is an oxygen atom, X ¹ is one equivalent of a metal cation and m is 1 include sodium octyl sulfate, potassium octyl sulfate, cesium octyl sulfate, lithium decyl sulfate and sodium decyl. Sulphate, sodium dodecyl sulphate, potassium dodecyl sulphate, lithium tetradecyl sulphate,
Sodium tetradecyl sulphate, potassium decyl sulphate, lithium hexadecyl sulphate, sodium oleyl sulphate, potassium hexadecyl sulphate can be mentioned.

Compounds in which Y ¹ is an oxygen atom and X ¹ is an ammonium cation represented by the above formula (I) -a include ammonium octyl sulfate, ammonium decyl sulfate, ammonium dodecyl sulfate and ammonium hexadecyl sulfate. Ammonium salts such as

Further, methyl ammonium hexyl sulfate, methyl ammonium octyl sulfate, methyl ammonium hexadecyl sulfate, ethyl ammonium hexyl sulfate, butyl ammonium nonadecyl sulfate, hexyl ammonium octadecyl sulfate, decyl ammonium ethyl sulfate, decyl ammonium butyl sulfate, decyl ammonium decyl Sulfate, dodecyl ammonium methyl sulfate, dodecyl ammonium ethyl sulfate, dodecyl ammonium octyl sulfate, tetradecyl ammonium butyl sulfate,
Primary ammonium salts such as pentadecyl ammonium methyl sulphate, hexadecyl ammonium butyl sulphate, hexadecyl ammonium octyl sulphate, hexadecyl ammonium decyl sulphate and hexadecyl ammonium dodecyl sulphate can be mentioned.

Dimethyl ammonium hexyl sulfate, dimethyl ammonium octyl sulfate,
Dimethyl ammonium tetradecyl sulfate, diethyl ammonium octadecyl sulfate, butyl methyl ammonium tetradecyl sulfate, hexyl methyl ammonium tetradecyl sulfate, decyl methyl ammonium methyl sulfate, decyl ethyl ammonium ethyl sulfate, decyl methyl ammonium octyl sulfate, dodecyl methyl ammonium methyl sulfate, tetra Decylmethylammonium methylsulfate, tetradecylethylammonium sulfate, pentadecylmethylammonium methylsulfate, pentadecylethylammonium ethylsulfate, hexadecylmethylammonium methylsulfate, hexadecylethylammonium ethylsulfate Shiki secondary ammonium salt, and the like.

Further, trimethyl ammonium octyl sulfate, trimethyl ammonium decyl sulfate, butyl dimethyl ammonium decyl sulfate,
Hexyl dimethyl ammonium dodecyl sulfate,
Decyldimethylammonium methylsulfate, decyldimethylammonium tridecylsulfate, dodecyldiethylammonium ethylsulfate, dodecyldibutylammonium butylsulfate, dodecyldimethylammonium tetradecylsulfate, tetradecyldimethylammonium methylsulfate, tetradecylmethylethylammonium methylsulfate, pentadecyldimethyl Examples thereof include tertiary ammonium salts such as ammonium methyl sulfate, hexadecyldimethylammonium methylsulfate, and hexadecylmethylethylammonium ethylsulfate.

Further, tetramethylammonium hexyl sulphate, tetraethylammonium tridecyl sulphate, butyl trimethylammonium octyl sulphate, decyl trimethylammonium methyl sulphate, decyl triethylammonium ethyl sulphate, decyl trimethylammonium hexadecyl sulphate, pentadecyl trimethylammonium methyl sulphate, penta Quaternary ammonium salts such as decyldimethylethylammonium ethylsulfate are included.

Among these, lithium decyl sulfate,
Sodium decyl sulfate, sodium dodecyl sulfate, potassium dodecyl sulfate, lithium tetradecyl sulfate, sodium tetradecyl sulfate, lithium hexadecyl sulfate, sodium oleyl sulfate, dodecyl ammonium ethyl sulfate, dodecyl methyl ammonium methyl sulfate, decyl methyl ammonium methyl sulfate, decyl ethyl Ammonium ethyl sulfate, tetradecyl ethyl ammonium ethyl sulfate, tetradecyl methyl ethyl ammonium ammonium sulfate, pentadecyl ethyl ammonium ethyl sulfate, hexadecyl methyl ammonium methyl sulfate, hexadecyl ethyl ammonium ethyl sulfate, decyl di Tylammonium methylsulfate, hexadecyldimethylammonium methylsulfate, pentadecyldimethylammonium methylsulfate, hexadecylmethylethylammoniumethylsulfate, pentadecyldimethylethylammoniumethylsulfate, decyldimethylammoniumtridecylsulfate, tetradecyldimethylammoniummethylsulfate, dodecyl Diethyl ammonium ethyl sulfate, tetradecyl diethyl ammonium ethyl sulfate, decyl trimethyl ammonium methyl sulfate, pentadecyl trimethyl ammonium methyl sulfate, and decyl triethyl ammonium ethyl sulfate are more preferably used.

Stabilizers of formula (II)

[0068]

Embedded image ^{+ X 2 -A 2 -Y 1 -SO} 3 - where ...... (II), A ² is a divalent hydrocarbon group, ⁺ X ² is 2
It is a quaternary ammonium cation or phosphonium cation, and Y ¹ has the same definition as above. In the formula (II), the divalent hydrocarbon group divalent saturated aliphatic hydrocarbon group of A ² is preferred. As this saturated aliphatic hydrocarbon group, those having 1 to 20 carbon atoms are more preferable.

⁺ X ² is an ammonium cation or a phosphonium cation. As the ammonium cation, the following formula (II) -a is used.

[0070]

Embedded image

[Here, R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom or a monovalent hydrocarbon group. ]
The cation represented by is preferred.

As the monovalent hydrocarbon group such as R ^{9 and the} like, the same ones as exemplified for the above formula (I) -a can be exemplified here.

The phosphonium cation is represented by the following formula (II) -b.

[0074]

Embedded image

[Here, R ¹² , R ¹³ and R ¹⁴ are each independently a hydrogen atom or a monovalent hydrocarbon group. ] Is preferable. As the monovalent hydrocarbon group represented by R ^{12 and the} like, the same groups as those exemplified for the above formula (I) -b can be exemplified.

The following compounds can be illustrated as specific examples of the compound represented by the above formula (II).

[0077]

Embedded image

Stabilizers of formula (III)

[0079]

[Chemical 12]

Here, A ³ is an n-valent hydrocarbon group,
⁺ X ³ is an ammonium cation or a phosphonium cation, R is a monovalent hydrocarbon group, and n is 2 to 4
And the definition of Y ¹ is the same as above.

The n-valent hydrocarbon group of A ³ is preferably, for example, an n-valent saturated aliphatic hydrocarbon group, aromatic hydrocarbon group or saturated aliphatic-aromatic hydrocarbon group.

Examples of the ammonium cation and the phosphonium cation for ⁺ X ³ include those represented by the above formulas (II) -a and (II) -b, respectively.

R is a monovalent hydrocarbon group, examples of which are preferably an alkyl group, an aryl group and an aralkyl group. The alkyl group preferably has 1 to 20 carbon atoms, the aryl group preferably has 6 to 20 carbon atoms, and the aralkyl group preferably has 7 to 20 carbon atoms.

N is 2, 3 or 4, and Y ¹ is a single bond or an oxygen atom as defined above.

The following compounds may be mentioned as specific examples of the compound represented by the above formula (III). Y ¹
Is a single bond, ⁺ X ³ is an ammonium cation represented by the formula (II) -a, and n is 2,

[0086]

Embedded image

[0087]

Embedded image

Y ¹ is an oxygen atom and ⁺ X ³ is the above formula (I
I) -ammonium cation represented by a, and when n is 2, the compound is

[0089]

Embedded image

Y ¹ is a single bond and ⁺ X ³ is the above formula (II).
A compound having a phosphonium cation represented by -b, and n being 2,

[0091]

Embedded image

Y ¹ is an oxygen atom and ⁺ X ³ is the above formula (I
I) -b is a phosphonium cation, and when n is 2, the compound is

[0093]

Embedded image

Stabilizers of formula (IV)

[0095]

Embedded image

Here, A ⁵ is a monovalent or divalent hydrocarbon group, A ⁴ is a divalent hydrocarbon group, and Ad ¹ and Ad ² are the same or different --SO ₂ --O--SO
_{2 -, - SO 2 -O-} CO- or -CO-O-SO ₂
Is an acid anhydride group selected from: and k is 0 or 1. However, when k is 0,-(Ad ² -A ⁵ ) _k represents a hydrogen atom or a bond for connecting A ⁴ and A ⁵ (in this case, A ⁵ is a divalent hydrocarbon group). Or a single bond).

The compound represented by the above formula (IV) is conveniently represented by the following formula (IV) -1 according to the definition of k.

[0098]

Embedded image A ⁵ —Ad ¹ —A ⁴ —Ad ² —A ⁵ (IV) -1 [wherein the definitions of A ⁴ , Ad ¹ and Ad ² are the same as in formula (IV) above, and A ⁵ is a monovalent hydrocarbon group. ] The compound represented by the following formula (IV) -2

[0099]

Embedded image A ⁵ —Ad ¹ —A ⁴ —H (IV) -2 [wherein, Ad ¹ and A ^{4 have} the same definitions as in the above formula (IV), and A ⁵ is a monovalent carbon It is a hydrogen group. ] The compound and the following formula (IV) -3 represented by

[0100]

[Chemical 21]

[Here, Ad ¹ and A ⁴ are defined by the above formula (I
Same as V) and A ⁵ is a divalent hydrocarbon group or a single bond. ] The compound represented by can be displayed separately.

The above formulas (IV), (IV) -1 and (IV)-
In 2, the monovalent hydrocarbon group represented by A ⁵ is
For example, an alkyl group, an aryl group or an aralkyl group can be mentioned as a preferable example. The alkyl group preferably has 1 to 20 carbon atoms, the aryl group preferably has 6 to 20 carbon atoms, and the aralkyl group preferably has 7 to 20 carbon atoms.

In the above formulas (IV) and (IV) -3, examples of the divalent hydrocarbon group represented by A ⁵ include an alkylene group, an arylene group and an aralkylene group. The alkylene group preferably has 1 to 20 carbon atoms, the arylene group preferably has 6 to 20 carbon atoms, and the aralkyl group preferably has 7 to 20 carbon atoms.

A ⁴ is a divalent hydrocarbon group, and examples thereof include the same as the divalent hydrocarbon group of A ⁵ .

Ad ¹ and Ad ² are the same or different and each is an acid anhydride group of --SO ₂ --O--SO _2- , --SO ₂ --O--CO-- or --CO--O--SO _2-. is there. These acid anhydride groups are anhydride groups between sulfonic acid and sulfonic acid (--SO ₂ --O--SO _2- ) or anhydride groups between sulfonic acid and carboxylic acid (--SO _2- ).
₂ —O—CO— or —CO—O—SO ₂ —).

The sulfonic acid compound is a monovalent or divalent sulfonic acid compound, and more specifically, methylsulfonic acid, ethylsulfonic acid, propylsulfonic acid, butylsulfonic acid, hexylsulfonic acid, decylsulfonic acid, Hexadecyl sulfonic acid, phenyl sulfonic acid, p
-Toluenesulfonic acid, dodecylbenzenesulfonic acid,
Octadecylbenzenesulfonic acid, benzenedisulfonic acid, toluenedisulfonic acid and the like are used.

Similarly, the carboxylic acid compound is a monovalent or divalent carboxylic acid compound, and specifically, acetic acid, propionic acid, butyric acid, valeric acid, stearic acid, myristic acid, oleic acid, benzoic acid, phenyl. Acetic acid, toluic acid, succinic acid, glutaric acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. are used.

The following compounds may be mentioned as specific examples of the compound represented by the above formula (IV).

As the compound represented by the formula (IV) -1

[0110]

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[0111]

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As the compound represented by the formula (IV) -2

[0113]

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[0114]

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[0115]

[Chemical formula 26]

As the compound represented by the formula (IV) -3

[0117]

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Among the stabilizers of the above formulas (I) to (IV), the phosphonium or ammonium salt type stabilizer itself is stable even at 200 ° C. or higher, and when added to the polymer, the catalyst is quickly detoxified, The polymer can be obtained. Among such stabilizers, ammonium salts of sulfonic acids and phosphonium salts are preferable, and further the above-mentioned salts of dodecylbenzenesulfonic acid such as tetrabutylphosphonium dodecylbenzenesulfonic acid salts and paratoluene such as paratoluenesulfonic acid tetrabutylammonium salts. The above salts of sulfonic acids are preferred.

In the method of the present invention, at least one selected from the group consisting of the compounds represented by the above formulas (I) to (IV).
The amount of the stabilizer is 0.1% per mol of the main polycondensation catalyst selected from alkali metal compounds and alkaline earth metal compounds.
It is preferable to use it in a ratio of 5 to 50 mol, preferably 0.5 to 10 mol, and more preferably 0.8 to 5 mol. This usually corresponds to the use of 0.01 to 500 ppm with respect to the polycarbonate produced.

In the method for producing a polycarbonate according to the present invention, it is also preferable to add an epoxy compound together with the above stabilizer. As such an epoxy compound, a compound having one or more epoxy groups in one molecule is used.

Specifically, epoxidized soybean oil, epoxidized linseed oil, phenyl glycidyl ether, acryl glycidyl ether, t-butylphenyl glycidyl ether, 3,4-epoxycyclohexylmethyl-3,4 '.
-Epoxy cyclohexyl carboxylate, 3,4-
Epoxy-6-methylcyclohexylmethyl-3 ',
4'-epoxy-6'-methylcyclohexylcarboxylate, 2,3-epoxycyclohexylmethyl-
3 ', 4'-epoxycyclohexylcarboxylate, 4- (3,4-epoxy-5-methylcyclohexyl) butyl-3', 4'-epoxycyclohexylcarboxylate, 3,4-epoxycyclohexylethylene oxide, cyclohexylmethyl-3 , 4-epoxycyclohexylcarboxylate, 3,4-epoxy-
6-methylcyclohexylmethyl-6'-methylcyclohexylcarboxylate, bisphenol A diglycidyl ether, tetrabromobisphenol A glycidyl ether, phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, bis-epoxydicyclopentadiene Phenyl ether, bis-epoxy ethylene glycol, bis-epoxy cyclohexyl adipate, butadiene diepoxide, tetraphenyl ethylenepoxide, octyl epoxytalate, epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane, 3, 5-dimethyl-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'-epoxycyclohexylcarboxylate, 4,6-dimethyl-2,3-epoxycyclohexyl-3', 4'-epoxycyclohexylcarboxylate, 4,5-epoxy tetrahydrophthalic anhydride, 3-t-butyl-4,5
-Epoxy tetrahydrophthalic anhydride, diethyl-4,
5-epoxy-cis-1,2-cyclohexyldicarboxylate, di-n-butyl-3-t-butyl-4,5
-Epoxy-cis-1,2-cyclohexyl dicarboxylate and the like can be mentioned.

These may be used alone or in combination of two or more. Of these, alicyclic epoxy compounds are preferably used, and 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexylcarboxylate is particularly preferably used.

In the present invention, it is preferable to add such an epoxy compound to the polycarbonate in an amount of 1 to 2000 ppm, preferably 1 to 1000 ppm.

When the epoxy compound is added in the above amount as described above, even if the stabilizer is excessively left in the polycarbonate, it reacts with the epoxy compound to be detoxified,
Finally, it becomes possible to obtain a polycarbonate having excellent hue stability, excellent heat resistance, and particularly improved water resistance.

In the method for producing a polycarbonate according to the present invention, a phosphorus compound may be added together with the above stabilizer. As such a phosphorus compound, phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid, polyphosphoric acid, phosphoric acid ester and phosphorous acid ester can be used.

Specific examples of such a phosphoric acid ester include, for example, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, trioctadecyl phosphate, distearyl pentaerythrityl diphosphate, tosyl (2 -Chloroethyl) phosphate, trialkyl phosphate such as tris (2,3-dichloropropyl) phosphate, tricycloalkyl phosphate such as tricyclohexyl phosphate,
Examples thereof include triphenyl phosphate, tricresyl phosphate, tris (nonylphenyl) phosphate, and triaryl phosphate such as 2-ethylphenyldiphenylphosphate.

Examples of the phosphite include compounds represented by the following general formula.

[0128]

Embedded image P (OR) ₃ (wherein, R is an alicyclic hydrocarbon group, an aliphatic hydrocarbon group or an aromatic hydrocarbon group. These may be the same or different.) Examples of the compound represented by such a formula include trimethylphosphite, triethylphosphite, tributylphosphite, trioctylphosphite, tris (2-ethylhexyl) phosphite, trinonylphosphite, tridecylphosphite, trioctadecyl. Phosphite, tristearyl phosphite, tris (2-chloroethyl) phosphite, tris (2,3-
Trialkylphosphites such as dichloropropyl) phosphite, tricycloalkylphosphites such as tricyclohexylphosphite, triphenylphosphite, tricresylphosphite, tris (ethylphenyl) phosphite, tris (2,4-diphenylphosphite. Triaryl phosphite such as -t-butylphenyl) phosphite, tris (nonylphenyl) phosphite, tris (hydroxyphenyl) phosphite, phenyldidecylphosphite, diphenyldecylphosphite, diphenylisooctylphosphite, phenyliso Examples include octyl phosphite, arylalkyl phosphite such as 2-ethylhexyl diphenyl phosphite, and the like.

Further, as phosphorous acid esters, distearyl pentaerythrityl diphosphite, bis (2,4
-Di-t-butylphenyl) pentaerythrityl diphosphite and the like. Among these, especially Tris (2,4-
Di-t-butylphenyl) phosphite is preferably used.

These compounds can be used alone or in combination. These may be added separately or may be added simultaneously. In the present invention, the phosphorus compound as described above is added to the polycarbonate resin in an amount of 10 to 1000 ppm, preferably 50 to 500 ppm.
Can be added in an amount of.

In the present invention, the method of adding the epoxy compound and phosphorus compound as described above to the reaction product polycarbonate is not particularly limited. For example, these may be added while the reaction product polycarbonate is in a molten state, or may be added after re-melting after pelletizing the polycarbonate once. In the former case, these may be added while the polycarbonate, which is the reaction product in the molten state reactor or extruder obtained after the completion of the polycondensation reaction, is in the molten state,
It is also possible to add a stabilizer and knead while the polycarbonate obtained by the polycondensation reaction is pelletized from the reactor through the extruder.

At this time, each of these compounds may be added simultaneously or separately. When these compounds are added in combination, the order of addition is not limited.

In the present invention, the polycarbonate obtained as above is added to the polycarbonate within the range not impairing the object of the present invention.
Heat resistance stabilizer, ultraviolet absorber, release agent, colorant, antistatic agent, slip agent, anti-locking agent, lubricant, anti-fog agent,
Natural oil, synthetic oil, wax, organic filler, inorganic filler and the like may be added. Such additives may be added at the same time as the aromatic dihydroxy compound or separately.

[0134]

EFFECTS OF THE INVENTION According to the present invention, when a polycarbonate is produced, the melted Hazen color number at a specific temperature of a mixture of an aromatic dihydroxy compound and a carbonic acid diester used as a raw material is set to a specific value or less, so that a yellow color or the like is obtained. It is possible to obtain a polycarbonate that is not colored and is particularly excellent in color tone and can be sufficiently used for optical applications.

[0135]

EXAMPLES Examples will be described below. Unless otherwise specified,% and parts in the examples are% by weight or parts by weight. The physical properties of the polycarbonate obtained in the following examples were measured as follows.

Viscosity average molecular weight: A methylene chloride solution of 0.7 g / dl was used to measure the intrinsic viscosity using an Ubbelohde viscometer, and the viscosity average molecular weight (M) was determined by the following formula. [Η] = 1.23 × 10 ⁻⁴ M ^0.83 Color tone (b value): The Lab value of the pellet is N made by Nippon Denshoku Industries Co., Ltd.
It was measured by the reflection method using D-1001DP, and the b value was used as a measure of yellowness.

Melt Hazen Color Number (APHA): JIS
Based on the color number test method shown in K-4101, diameter 2
Using a flat-bottom Pyrex colorimetric tube having a thickness of 3 mm and a thickness of 1.5 mm, the Hazen color number at a liquid depth of 140 mm was measured in the molten state by comparing with a Hazen standard colorimetric solution. Also, J
The aluminum ingot hot bath shown in IS K-4101 was used, and it was also used for holding the molten state.

Example 1 Diphenyl carbonate (lot A manufactured by Bayer) was washed with hot water of pH 8.0 at 85 ° C., and then washed three times with hot water of 85 ° C. having an electric conductivity of 10 μS / cm or less, 1 x for 1 mol of diphenyl carbonate
Add 10 ⁻⁷ mol of sodium hydroxide and distill under reduced pressure to 80
% Diphenyl carbonate and bisphenol A (manufactured by Nippon Steel Chemical Lot A) were mixed in a ratio of 1: 1 by weight, and had a melted Hazen color number of 5 at 175 ° C. in the atmosphere and 175 ° C. for 5 hours. It was confirmed that the molten Hazen color number after holding in the air was 15.

49.2 kg of the above diphenyl carbonate prepared in a reactor equipped with a stirrer and a distillation column, 50 kg of the above bisphenol A (lot A manufactured by Nippon Steel Chemical Co., Ltd.), 10 mg of sodium hydroxide as a catalyst and 1.6 g of tetramethylammonium hydroxide. The charged nitrogen was replaced.
The mixture was heated to 150 ° C. and dissolved with stirring. Then, the degree of vacuum was set to 30 mmHg and heated to 200 ° C., and most of the phenol was distilled off in 1 hour. Then, the temperature was raised to 270 ° C., the pressure was reduced to 1 mmHg, and the reaction was carried out for 3 hours to obtain a polycarbonate. The obtained polycarbonate was cut with a cutter into pellets. The results of measuring the viscosity average molecular weight and the hue (b value) of the polycarbonate are shown in Table 1.

Example 2 Diphenyl carbonate (Bayer lot A) was washed with hot water of pH 8.0 at 85 ° C. and then with hot water of 85 ° C. having an electric conductivity of 10 μs / cm or less three times. 1 x for 1 mol of diphenyl carbonate
Add 10 ⁻⁷ mol of sodium hydroxide and distill under reduced pressure to 80
% Diphenyl carbonate and bisphenol A (manufactured by Mitsui Toatsu Co., Ltd.) were mixed at a ratio of 1: 1 by weight, and had a melted Hazen color number of 10 at 175 ° C. in the atmosphere and the atmosphere at 175 ° C. for 5 hours. A polymer was obtained in the same manner as in Example 1 except that diphenyl carbonate having a molten Hazen color number of 20 after holding and bisphenol A were used. The results of measuring the physical properties of the polymer are shown in Table 1.

Example 3 Diphenyl carbonate (Bayer lot A) was washed with hot water of pH 8.0 at 85 ° C. and then with hot water of 85 ° C. having an electric conductivity of 10 μS / cm or less three times. 5 × for 1 mol of diphenyl carbonate
Add 10 ^-8 mol of sodium hydroxide and distill under reduced pressure to 80
% Diphenyl carbonate and bisphenol A (Nippon Iron & Steel Co., Ltd. lot B) were mixed in a ratio of 1: 1 by weight, and had a melted Hazen color number of 15 at 175 ° C. in the atmosphere and 175 ° C. for 5 hours. A polymer was obtained in the same manner as in Example 1 except that diphenyl carbonate having a molten Hazen color number of 30 after being held in the air and bisphenol A were used. The results of measuring the physical properties of the polymer are shown in Table 1.
Shown in

Example 4 Diphenyl carbonate (Lot B, manufactured by Bayer) was washed with hot water having a pH of 8.0 at 85 ° C., and then twice with hot water having a conductivity of 10 μs / cm or less at 85 ° C. 5 × for 1 mol of diphenyl carbonate
90% by adding 10 ^-8 mol of sodium carbonate and distilling under reduced pressure
The diphenyl carbonate obtained in the yield and bisphenol A (lotus A manufactured by Nippon Steel Chemical Co., Ltd.) were mixed in a ratio of 1: 1 by weight, and had a molten Hazen color number of 5 at 175 ° C. in the atmosphere, and the atmosphere at 175 ° C. for 5 hours. A polymer was obtained in the same manner as in Example 1 except that diphenyl carbonate having a molten Hazen color number of 40 after holding and bisphenol A were used. The results of measuring the physical properties of the polymer are shown in Table 1.

[0143]

[Table 1]

[Comparative Example 1] In Example 1, diphenyl carbonate (Bayer lot A) was added at a pH of 85 ° C.
After washing with hot water of 8.0, wash twice with hot water of 85 ° C. having an electric conductivity of 10 μs / cm or less, add 1 × 10 ⁻⁸ mol of sodium hydroxide to 1 mol of diphenyl carbonate, and distill under reduced pressure. And bisphenol A (lot B manufactured by Nippon Steel Chemical Co., Ltd.) obtained in 90% yield were mixed at 1: 1 parts by weight to obtain a molten Hazen color number of 20 at 175 ° C. in air and 175 ° C. A polymer was obtained in the same manner as in Example 1 except that diphenyl carbonate and bisphenol A having a molten Hazen color number of 45 after being held in the atmosphere for 5 hours were used. The results of measuring polymer physical properties are shown in Table 2.

[Comparative Example 2] In Example 1, diphenyl carbonate (Bayer lot B) was added at a pH of 85 ° C.
After washing with hot water of 8.0, wash twice with hot water of 85 ° C. having an electric conductivity of 10 μs / cm or less, add 1 × 10 ⁻⁸ mol of sodium hydroxide to 1 mol of diphenyl carbonate, and distill under reduced pressure. The diphenyl carbonate and bisphenol A (lot B manufactured by Nippon Steel Chemical Co., Ltd.) obtained in a yield of 85% were mixed in a ratio of 1: 1 by weight, and had a molten Hazen color number of 30 at 175 ° C. in the atmosphere and 175 ° C. A polymer was obtained in the same manner as in Example 1 except that diphenyl carbonate and bisphenol A having a molten Hazen color number of 40 after being held in the atmosphere for 5 hours were used. The results of measuring polymer physical properties are shown in Table 2.

[Comparative Example 3] In Example 1, after diphenyl carbonate (manufactured by SNPE) was washed with hot water having a pH of 8.0 at 85 ° C, the conductivity of 85 was 10 µs / cm or less.
After washing twice with hot water at ℃, 1 × 10 ^-8 mol of sodium carbonate was added to 1 mol of diphenyl carbonate, and vacuum distillation was carried out to obtain diphenyl carbonate and bisphenol A (80% yield) (Mitsui Toatsu). And 1: 1 parts by weight of diphenyl carbonate having a melted Hazen color number of 15 at 175 ° C. in the air and a molten Hazen color number of 55 after being kept at 175 ° C. for 5 hours in the air. A polymer was obtained in the same manner as in Example 1 except that bisphenol A was used. The results of measuring the physical properties of the polymer are shown in Table 2.
Shown in

[Comparative Example 4] In Example 1, after diphenyl carbonate (manufactured by SNPE) was washed with hot water having a pH of 8.0 at 85 ° C, the conductivity of 85 was 10 µs / cm or less.
Washing once with hot water at ℃, diphenyl carbonate and bisphenol A (manufactured by Mitsui Toatsu) obtained in 90% yield by adding 1 × 10 ^-8 mol of sodium carbonate to 1 mol of diphenyl carbonate and distilling under reduced pressure. 1: 1 parts by weight of diphenyl carbonate having a molten Hazen color number of 30 at 175 ° C. in the atmosphere and a molten Hazen color number of 55 after being kept at 175 ° C. for 5 hours in the air. A polymer was obtained in the same manner as in Example 1 except that bisphenol A was used. The results of measuring the physical properties of the polymer are shown in Table 2.
Shown in

[Comparative Example 5] In Example 1, after diphenyl carbonate (manufactured by SNPE) was washed with hot water having a pH of 8.0 at 85 ° C, the conductivity of 85 was 10 µs / cm or less.
After washing once with hot water at ℃, 1 × 10 ^-8 mol of sodium carbonate was added to 1 mol of diphenyl carbonate and distilled under reduced pressure to obtain diphenyl carbonate and bisphenol A (manufactured by Alistec) in 90% yield. 1: 1 parts by weight were mixed, and the melting Hazen color number at 175 ° C. in the atmosphere was 40.
A polymer was obtained in the same manner as in Example 1 except that diphenyl carbonate and bisphenol A, which had a No. 70 melting point and a molten Hazen color number of 70 after being kept at 175 ° C. for 5 hours in the air, were used. The results of measuring polymer physical properties are shown in Table 2.

[0149]

[Table 2]

Claims (1)

[Claims] 1. When an aromatic polycarbonate is produced by polycondensing an aromatic dihydroxy compound and a carbonic acid diester under heating and melting to produce an aromatic polycarbonate, a 1: 1 part by weight mixture of the aromatic dihydroxy compound and the carbonic acid diester is heated in the air 175.
An aromatic dihydroxy compound and a carbonic acid diester having a molten Hazen color number of 20 or less at 0 ° C. and a molten Hazen color number of 40 or less after being held at 175 ° C. for 5 hours in the atmosphere are used. Process for producing aromatic polycarbonate.