JPH08104747A - Production of aromatic polycarbonate - Google Patents

Abstract

PURPOSE: To produce a polycarbonate excellent in color tone. CONSTITUTION: An arom. polycarbonate is produced by thermally melt reacting an arom. dihydroxy compd. with a carbonic diester in the presence of a compd. represented by the formula in an amt. of 10wt.ppm or higher but 3wt.% or lower based on the arom. dihydroxy compd. In the formula, R1 , R2 , R3 , and R4 are each independently H, 1-4C alkyl, or optionally substd. 6-10C aryl; and R5 is H, 1-6C alkyl, or optionally substd. 6-10C aryl.

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 an improved color tone.

[0002]

2. Description of the Related Art Polycarbonate resins obtained by interfacial polycondensation of aromatic dihydroxy compounds and phosgene are widely used for various purposes due to their excellent mechanical properties and thermal properties, but toxic phosgene is used. Therefore, there is a problem in safety, and use of methylene chloride as a solvent causes many problems such as environmental damage. Therefore, the transesterification method that does not use methylene chloride or phosgene has recently been in the limelight, but the polycarbonate resin obtained by the transesterification method is subject to heat history at high temperature for a long time, so that it is not possible to find one with excellent quality such as deterioration in color tone. I couldn't get it. For this reason, the polycarbonate obtained by the above method cannot be used in the field where a color tone is required.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have conducted extensive studies to find a transesterified polycarbonate having an excellent color tone, and have found that it is effective to allow a specific compound to exist in a specific value, and the present invention is completed. Came to.

[0004]

That is, according to the present invention, when an aromatic dihydroxy compound and a carbonic acid diester are reacted under heating and melting to produce an aromatic polycarbonate, 10 ppm by weight based on the aromatic dihydroxy compound is used.
A method for producing an aromatic polycarbonate, which comprises allowing the compound represented by the following formula (1) to be present in an amount of 3% by weight or less.

[0005]

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In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an optionally substituted aryl group having 6 to 10 carbon atoms. . Examples of the alkyl group having 1 to 4 carbon atoms include methyl group, ethyl group and propyl group. Examples of the substituent for the aryl group include an alkyl group such as a methyl group, an ethyl group and a propyl group, and examples of the aryl group include a phenyl group and a methylphenyl group.

R ₅ represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an optionally substituted aryl group having 6 to 10 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group and a propyl group. Examples of the substituent for the aryl group include an alkyl group such as a methyl group, an ethyl group and a propyl group, and examples of the aryl group include a phenyl group and a methylphenyl group.

As the compound represented by the formula (1), bisphenylmethane, 4-hydroxyphenylphenylmethane, 4-methylphenylphenylmethane, bis (4-hydroxyphenyl) methane, bis (4-methylphenyl) methane, bis ( 4-ethylphenyl) methane, 1,
1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-ethylphenyl) ethane, 1,1-bis (4
-Hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxy-3-methylphenyl) methane, 1- (4-hydroxyphenyl) -2-phenylethane, 1,1-bis (4-hydroxy) 3-methyl) ethane, 1,1-bis (4-hydroxy-3-methylphenyl) propane and the like can be mentioned.

In the present invention, the total amount of the compounds represented by the formula (1) is 10 weight pp with respect to the aromatic dihydroxy compound.
m or more and 3 wt% or less, preferably 200 wt ppm or more and 1 wt% or less, more preferably 500 wt ppm
It is characterized by being 0.3% by weight or less.

When the amount of the compound represented by the formula (1) is too small relative to the aromatic dihydroxy compound used, the color tone of the synthetic polycarbonate is remarkably deteriorated, and when it is too large, the physical properties of the polymer are deteriorated. 10 weight ppm
If it is less than 10, the color tone of the synthetic polycarbonate is remarkably deteriorated, and if it exceeds 10 ppm by weight, the polymer color tone is gradually improved with the increase of the addition amount.

When the amount exceeds 200 ppm by weight, the variation in the color tone of the synthetic polycarbonate is reduced and a polymer having an excellent color tone can be obtained. When the amount exceeds 500 ppm by weight, a polymer having an excellent color tone can be obtained more stably. 0.3% by weight
If it exceeds 1% by weight, variations in the physical properties of the polymer occur, and if it exceeds 1% by weight, the variations in the physical properties of the polymer become slightly large. Further, if it exceeds 3% by weight, the physical properties of the polymer are remarkably deteriorated, which is not preferable.

Any method can be used to adjust the amount of the compound represented by the formula (1) to the above value. For example, a method of preliminarily containing it in the raw material or a method of adding it in the middle of the reaction may be employed.

The aromatic dihydroxy compound used in the present invention is a compound represented by the following formula (2).

[0014]

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Is shown. R ₈ and R ₉ are the same or different and each represents an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 10 carbon atoms which may be substituted. 1 to 5 carbon atoms
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group and the like. Examples of the substituent to the aryl group include an alkyl group such as a methyl group, an ethyl group and a propyl group,
Examples of the aryl group include a phenyl group and a methylphenyl group.

R ₁₀ is an alkylene group having 3 to 8 carbon atoms. Examples of the alkylene group include a propylene group and a butylene group.

R ₆ and R ₇ are the same or different and each represents a halogen atom or an alkyl group having 1 to 5 carbon atoms. Examples of the halogen atom include chlorine and bromine. Examples of the alkyl group include a methyl group and a t-butyl group.

M and n are the same or different and are 0, 1 or 2.

As the compound represented by the formula (2), 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, 1,1
-Bis (4-hydroxyphenyl) cyclopentane,
Bis (hydroxyaryl) cycloalkanes such as 1,1-bis (hydroxyphenyl) cyclohexane,
Dihydroxy aryl ethers such as 4,4′-dihydroxy diphenyl ether, dihydroxy aryl sulfides such as 4,4′-dihydroxy diphenyl sulfide, dihydroxy aryl sulfoxides such as 4,4′-dihydroxy diphenyl sulfoxide, 4,
Dihydroxy aryl sulfones such as 4′-dihydroxy diphenyl sulfone are used. Especially 2,2-
Bis (4-hydroxyphenyl) propane is preferred.

As the carbonic acid diester used in the present invention, an optionally substituted aryl group having 6 to 10 carbon atoms,
Araalkyl group, C1-5 alkyl group, C3
Examples of the ester include cycloalkyl and the like. Specifically, diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate and the like are used. Diphenyl carbonate is particularly preferable.

Further, these carbonic acid diesters may contain a dicarboxylic acid or a dicarboxylic acid ester. The dicarboxylic acid or dicarboxylic acid ester is not particularly limited, and examples thereof include terephthalic acid, isophthalic acid, and diphenyl terephthalate.

When the above-mentioned carboxylic acid or dicarboxylic acid ester is used in combination with carbonic acid diester, a polyester polycarbonate can be obtained. The method for producing the polycarbonate of the present invention also includes the method for producing this polyester polycarbonate.

In producing the polycarbonate according to the present invention, the carbonic acid diester is used in an amount of 1.01 to 1.30 mol, preferably 1.02 to 1.20 mol, per 1 mol of the aromatic dihydroxy compound. Preferably.

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

As the polymerization catalyst, hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide and potassium hydroxide, alkali metal and alkaline earth metal salts of boron and aluminum hydroxides, and quaternary ammonium are used. salts,
Alkoxides of alkali metals and alkaline earth metals, organic acid salts of alkali metals and alkaline earth metals, zinc compounds, boron compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, onium compounds It is possible to use catalysts which are usually used for esterification reaction and transesterification reaction, such as antimony compounds and zirconium compounds, but not limited to these. When using a catalyst, only one kind may be used,
Two or more kinds may be used in combination.

The amount of these catalysts used is 0.000001 to 1% by weight, preferably 0.00001 to 0.5% by weight, more preferably 0.00001 to 0.1% by weight, based on the starting aromatic dihydroxy compound. It is selected in the range of.

The transesterification reaction of the aromatic dihydroxy compound and the carbonic acid diester of the present invention is carried out by distilling the hydroxy compound produced by stirring under heating in an inert gas atmosphere as is conventionally known. Be seen. The reaction temperature is usually in the range of 120 to 350 ° C. In the latter stage of the reaction, the system is depressurized to facilitate the distillation of the produced hydroxy compound and complete the reaction.

[0028]

EFFECT OF THE INVENTION According to the present invention, when a polycarbonate is produced, a certain amount of the compound represented by the formula (1) is present in the aromatic dihydroxy compound so that the color tone is not changed to yellow or the like. An excellent polycarbonate can be obtained.

[0029]

EXAMPLES Examples will be described below. Unless otherwise specified,% and parts in the examples are% by weight or parts by weight. In the following examples, the physical properties of polycarbonate 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 was determined by the following formula.

[0031]

[Equation 1] [η] = 1.23 × 10 ⁻⁴ M ^0.83 Color tone (b value): 2 mm thick press sheet Lab value is measured by the transmission method using ND-1001DP manufactured by Nippon Denshoku Industries Co., Ltd. B value was used as

Quantification of the compound represented by the formula (1): It was measured by a high performance liquid chromatograph using μBondapak C-18 manufactured by Waters Co. as a column.

[Example 1] 1370 parts of bisphenol A and 1350 parts of diphenyl carbonate prepared in a reactor equipped with a stirrer and a distillation column so that the content of 1,1-bis (4-hydroxyphenyl) ethane was 21 ppm (weight). Bisphenol A disodium salt 0.0016 as catalyst
A portion was charged and the atmosphere was replaced with nitrogen. 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., and the reaction was carried out for 2 hours under a reduced pressure of 1 mmHg to obtain a polycarbonate having a viscosity average molecular weight of 22400, which was cut with a cutter to obtain pellets. This was injection molded into a 2 mm thick test piece. The results of measuring the color tone (b value) are shown in Table 1.

[Example 2] In Example 1, the content of 1,1-bis (4-hydroxyphenyl) propane was adjusted to 28
A polymer was obtained in the same manner as in Example 1 except that bisphenol A adjusted to 0 ppm was used. The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.
Shown in

Example 3 In Example 1, the content of 1,1-bis (4-hydroxyphenyl) ethane was 670.
A polymer was obtained in the same manner as in Example 1 except that bisphenol A adjusted to ppm was used. The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.

Example 4 Bisphenol A as a catalyst
A polymer was obtained in the same manner as in Example 2 except that 0.0010 parts of disodium salt and 0.0040 parts of tetramethylammonium hydroxide were used. The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.

[Example 5] A polymer was obtained in the same manner as in Example 3 except that 0.0160 parts of tetramethylammonium acetate was used as a catalyst. The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.

[Example 6] In Example 1, the content of 1,1-bis (4-hydroxyphenyl) propane was adjusted to 0.
A polymer was obtained in the same manner as in Example 1 except that bisphenol A prepared at 54% by weight was used. The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.

Example 7 In Example 1, the content of 1,1-bis (4-hydroxyphenyl) ethane was 2.3.
A polymer was obtained in the same manner as in Example 1 except that bisphenol A prepared in a weight percentage was used. The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.

COMPARATIVE EXAMPLE 1 A polymer was prepared in the same manner as in Example 1 except that bisphenol A prepared in Example 1 containing 1,1-bis (4-hydroxyphenyl) ethane [bisphenol E] at 3 ppm was used. Got The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.

[Comparative Example 2] The same procedure as in Example 1 was carried out except that bisphenol A prepared in Example 1 containing 5% by weight of 1,1-bis (4-hydroxyphenyl) ethane [bisphenol E] was used. To obtain a polymer. The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.

Comparative Example 3 A polymer was obtained in the same manner as in Comparative Example 1 except that 0.0160 parts of tetramethylammonium acetate was used as a catalyst in Comparative Example 1. The results of measuring the viscosity average molecular weight and color tone (b value) of the polymer are shown in Table 1.

[0043]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Katsushi Sasaki 2-1, Hinodemachi, Iwakuni-shi, Yamaguchi Teijin Limited Iwakuni Research Center

Claims (1)

[Claims] 1. An aromatic dihydroxy compound and carbon dioxide
Aromatic polycarbonates
To produce aromatic dihydroxy compounds
The amount of 10 wt ppm or more and 3 wt% or less
Characterized in that the compound represented by (1) is allowed to exist.
A method for producing an aromatic polycarbonate. [Chemical 1][R in the formula₁, R₂, R₃And R_FourEach independently, water
Elemental atom, alkyl group having 1 to 4 carbon atoms or 6 to 1 carbon atoms
0 represents an optionally substituted aryl group. R ₅Is
Hydrogen atom, alkyl group having 1 to 6 carbon atoms or 6 to carbon atoms
10 represents an optionally substituted aryl group. ]