JPH111552A - Production of aromatic polycarbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aromatic polycarbonate high in activity and slight in its thermal stability loss and discolored matter formation due to catalyst residues, etc., by autocondensation reaction of a specific aromatic dihydroxy compound's bisalkyl carbonic ester as feedstock in the presence of a specific quaternary ammonium salt as catalyst. SOLUTION: This aromatic polycarbonate is obtained by autocondensation reaction of an aromatic dihydroxy compound (esp. bisphenol A)'s bisalkyl carbonic ester of formula I (R<1> and R<2> are each a 1-10C alkyl, etc.; Z is a divalent aromatic residue) [e.g. 4-hydroxyphenol's bis(methyl carbonate)] in the presence of 1×10<-6> to 1×10<-2> mol, per mol of the feedstock, of a quaternary ammonium salt of formula II (R<11> to R<14> are each a 1-30C alkyl or cycloalkyl; X is a halogen, acetyl, etc.), (esp. tetrabutylammonium acetate) under normal pressure to 10 mmHg at 100-350 deg.C for 20 min to 10 h.

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 by self-condensing a bisalkyl carbonate.

[0002]

2. Description of the Related Art Conventionally, as a method for producing an aromatic polycarbonate by self-condensation of a bisalkyl carbonate, a method of self-condensing bisphenol A bismethyl carbonate as a raw material has been proposed. A method using a tin compound (German Patent No. 2736063, Japanese Patent Application Laid-Open No. 57-2334), a method using a metal element belonging to groups IIB, IIIB, IVA and IVB of the periodic table and a compound thereof (Japanese Patent Application Laid-Open No. 63-2
05318) and a method of using various metals as catalysts (Japanese Patent Application Laid-Open No. 2-251522). There was a problem.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing an aromatic polycarbonate using a catalyst which is excellent in activity and has little loss of thermal stability due to catalyst residue or the like and little generation of coloring substances. And

[0004]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems, the present inventors have completed the present invention having the following contents. (1) A method for producing an aromatic polycarbonate, wherein a bisalkyl carbonate of an aromatic dihydroxy compound represented by the formula (A) is used as a raw material and a quaternary ammonium salt represented by the formula (B) is self-condensed as a catalyst.

[0005]

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(Wherein R ¹ and R ^{2 each} have 1 to 10 carbon atoms)
Or a cycloalkyl group having 3 to 10 carbon atoms, which may be the same or different from each other. Z
Is a divalent aromatic residue. )

[0007]

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(Wherein R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are
An alkyl group or a cycloalkyl group having 1 to 30 carbon atoms, which may be the same or different from each other. X
Is a halogen atom, a hydroxyl group, an acetyl group, a phenoxy group or an alkoxy group. )

(2) The method for producing an aromatic polycarbonate according to claim 1, wherein the quaternary ammonium salt used as the catalyst is tetrabutylammonium acetate. (3) As the bisalkyl carbonate of the aromatic dihydroxy compound represented by the formula (A), the above (1) or (1) wherein a raw material in which R ¹ and R ² are methyl groups and the aromatic dihydroxy compound is bisphenol A is used. The method for producing an aromatic polycarbonate according to 2).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, a bisalkyl carbonate of an aromatic dihydroxy compound represented by the formula (A) is used as a raw material.

[0011]

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(In the formula, R ¹ , R ² and Z have the same meanings as described above.) In the bisalkyl carbonate of the aromatic dihydroxy compound represented by the formula (A), R ¹ and R ² are, for example, methyl An alkyl group having 1 to 10 carbon atoms such as ethyl, propyl, isopropyl, butyl, amyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl,
A cycloalkyl group having 3 to 10 carbon atoms such as cyclohexyl is exemplified. Furthermore, the hydrogen atom of these alkyl groups or cycloalkyl groups may be substituted with an alkoxy group, an ester group, or a nitrile group, respectively. R ¹ and R ² may be the same or different. Preferably, R ¹ , R ²
Both are preferably methyl groups.

Z is a divalent aromatic residue of an aromatic dihydroxy compound. Examples of such an aromatic residue include a phenylene group, a naphthylene group, a biphenylene group, and a divalent aromatic residue represented by the general formula (C).

[0014]

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In the formula (C), Z ¹ and Z ² are divalent aromatic groups, for example, phenylene group, naphthylene group,
It is a biphenylene group or the like, which may be the same or different. T is a single bond or -O-, -CO-,-
_{S -, - SO 2 -,} - CO 2 -, - CON (R 3) -,

[0016]

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And a divalent group such as (Where R ³ , R
⁴ , R ⁵ and R ⁶ may be the same or different and represent a hydrogen, an alkyl group, an alkoxy group or a cycloalkyl group, preferably an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group. k represents an integer of 3 to 11. Further, in Z, Z ¹ and Z ² , a hydrogen atom may be substituted with an alkoxy group, an ester group, a nitrile group or the like.

Representative examples of such bisalkyl carbonates of aromatic dihydroxy compounds include those obtained from the reaction of an alkyl chloroformate with a dialkali metal salt of bisphenol A (Japanese Patent Publication No. 37-3296). As specific compound names, for example, bis (methyl carbonate) of 4-hydroxyphenol, bis (methyl carbonate) of 3-hydroxyphenol, 1,1-bis (4-hydroxyphenyl) -butane as bismethyl carbonate Bis (methyl carbonate), bis (4-hydroxyphenyl) -methane bis (methyl carbonate), 2-methyl-1,1-bis (4-hydroxyphenyl) -propane bis (methyl carbonate), 2,2 -Bis (3,5-dimethyl-4
-Hydroxyphenyl) -propane bis (methyl carbonate), bis (3,5-dimethyl-4-hydroxyphenyl) -sulfone bis (methyl carbonate), bis (3,5-dimethyl-4-hydroxyphenyl) -ether Bis (methyl carbonate), 4,
Bis (methyl carbonate) of 4'-dihydroxybenzophenone, 1,1-bis (4-hydroxyphenyl)
-Bis (methyl carbonate) of ethane, 1-ethyl-
Bis (methyl carbonate) of 1,1-bis (4-hydroxyphenyl) -propane, bis (methyl carbonate) of 1,1-bis (4-hydroxyphenyl) -cyclohexane, 1,1-bis (4-hydroxyphenyl) )
Bis (methyl carbonate) of cyclododecane, bis (methyl carbonate) of bis (4-hydroxyphenyl) -phenylmethane, bis (methyl carbonate) of bis (4-hydroxyphenyl) -naphthylmethane,
Bis (4-hydroxyphenyl)-(4-isopropylphenyl) -methane bis (methyl carbonate),
Bis (methyl carbonate) of 2,2-bis (4-hydroxyphenyl) -propane, bis (methyl carbonate) of 2,2-bis (4-hydroxyphenyl) -butane, 2,2-bis (4-hydroxyphenyl) ) -Hexane bis (methyl carbonate), 2,2-bis (3,5-dicyclolo-4-hydroxyphenyl) -propane bis (methyl carbonate), 2,2-bis (4-hydroxyphenyl) -pentane Bis (methyl carbonate), bis (methyl carbonate) of 2,2-bis (4-hydroxyphenyl) -nonane, bis (methyl carbonate) of diphenyl-bis (4-hydroxyphenyl) -methane, 4-methyl-2, Bis (methyl carbonate) of 2-bis (4-hydroxyphenyl) -pentane, 4,4-bis 4-hydroxyphenyl) - heptane bis (methyl carbonate), 1-naphthyl-1,1-bis (4-hydroxyphenyl) - bis ethane (methyl carbonate), 1-phenyl -
Bis (methyl carbonate) of 1,1-bis (4-hydroxyphenyl) -ethane, 2-cyclohexyl-4-
Bis (methyl carbonate) of (4-hydroxyphenyl) isopropylphenol, 2-methoxy-4- (4
Bis (methyl carbonate) of -hydroxyphenyl) isopropylphenol, bis (methyl carbonate) of 1,2-bis (4-hydroxyphenyl) -ethane,
2,2-bis (3-chloro-4-hydroxyphenyl)
Bis (methyl carbonate) of propane, bis (methyl carbonate) of 2-isopropyl-4- (4-hydroxyphenyl) isopropylphenol, bis (methyl carbonate) of 2,2-bis (3-methyl-4-hydroxyphenyl) -propane Methyl carbonate), bis (methyl carbonate) of 2,2-bis (3-fluoro-4-hydroxyphenyl) -propane, bis (methyl carbonate) of 1,10-bis (4-hydroxyphenyl) -decane, bis ( Bis (methyl carbonate) of 3,5-dichloro-4-hydroxyphenyl) -methane, 2,2-
Bis (3,5-dibromo-4-hydroxyphenyl)-
Bis (methyl carbonate) of propane, bis (methyl carbonate) of 1,1-bis (3,5-dichloro-4-hydroxyphenyl) -cyclohexane, bis (4-
Bis (methyl carbonate) of hydroxyphenyl) -sulfide, bis (methyl carbonate) of bis (3-methyl-4-hydroxyphenyl) -sulfide, bis (methyl carbonate) of bis (4-hydroxyphenyl) -sulfoxide, bis ( 4-hydroxyphenyl)
Bis (methyl carbonate), bis (3-
Bis (methyl carbonate) of chloro-4-hydroxyphenyl) -sulfone, bis (methyl carbonate) of ethylene glycol-bis (4-hydroxyphenyl) ether, bis (methyl carbonate) of 1,4-bis (4-hydroxyphenyl) -butane Methyl carbonate), 1,4-
Bis (methyl carbonate) of bis (4-hydroxyphenylisopropyl) -benzene, 1,4-bis (3-
Bis (methyl carbonate) of chloro-4-hydroxyphenyl) -benzene, bis (methyl carbonate) of bis (4-hydroxyphenyl) ether, 1,4-
Bis (4-hydroxyphenoxy) -benzene bis (methyl carbonate), 1,4-bis (4-hydroxyphenylmethyl) -benzene bis (methyl carbonate), 1,4-bis (4-hydroxyphenylsulfonyl)- Bis (methyl carbonate) of benzene, bis (methyl carbonate) of bis (3,5-dimethyl-4-hydroxyphenyl) -methane, bis (methyl carbonate) of bis (3,5-dimethyl-4-hydroxyphenyl) -sulfide ), 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybenzophenone bis (methyl carbonate), and the like.

Bisethyl carbonates wherein the methyl group of the bismethyl carbonate is replaced with an ethyl group,
Bispropyl carbonate substituted for various propyl groups, bisbutyl carbonate substituted for various butyl groups, bisamyl carbonate substituted for various amyl groups, bishexyl carbonate substituted for various hexyl groups, replaced with cyclopropyl group Biscyclopropyl carbonate can also be used.

Further, in the dialkyl carbonates having different alkyl groups, for example, the above-mentioned bismethyl carbonates, one of the methyl groups may be substituted with an alkyl group having 2 to 10 carbon atoms such as an ethyl group, a propyl group or a butyl group, or a cycloalkyl group. And dialkyl carbonates can also be used. These bisalkyl carbonates may be used alone or in combination of two or more. Among them, bisphenol A bismethyl carbonate, which is inexpensive, easily available, and stable in quality, is particularly preferable.

The reaction conditions vary depending on the type of raw materials, the type of catalyst used and the amount used, but the reaction pressure is usually from normal pressure to 10 mmHg, and the reaction temperature is from 100 to 350 ° C, preferably from 150 to 340 ° C. And the reaction time is 20
It can be selected in the range of minutes to 10 hours, preferably 1 hour to 8 hours. Further, in this reaction, the reaction can be promoted by discharging dialkyl carbonate, which is a by-product, to the outside of the system, so that a stirring operation, and further, an operation of replacing and removing with an inert gas such as nitrogen gas or carbon dioxide gas may be used in combination. It is effective.

In the present invention, a quaternary ammonium salt represented by the formula (B) is used as a catalyst in the above reaction.

[0023]

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(Wherein R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are
An alkyl group having 1 to 30 carbon atoms or a cycloalkyl group having 3 to 30 carbon atoms, which may be the same or different. X represents a halogen atom, a hydroxyl group, an acetyl group,
A phenoxy group and an alkoxy group. Specific examples include tetrabutylammonium acetate, tetramethylammonium hydroxide and the like. These catalysts may be used alone or in combination of two or more. Among them, particularly, tetrabutylammonium acetate can be suitably used.

The amount of the catalyst used is usually 1 × 10 ^-6 to 1 mol of the starting bisalkyl carbonate.
It can be selected in the range of 1 × 10 ⁻² mol, preferably 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol. In the present invention, if necessary, phloroglucin; trimellitic acid; 1,1,1-tris (4-hydroxyphenyl) ethane; 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl] -4
-[Α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene; α, α', α" -tris (4-hydroxyphenyl) -1,3,5-triisopropylbenzene as a branching agent It can also be used.

After a relatively low molecular weight polycarbonate is produced by the method of the present invention, it can be further increased in molecular weight by solid phase polymerization or the like.

[0027]

The present invention will be described in more detail with reference to Examples and Comparative Examples. Example 1 0.17 g (0.5 mmo) of bisphenol A bismethyl carbonate was placed in a 20 ml glass test tube.
l), and a solution of tetrabutylammonium acetate in 0.01 M acetone was added to 5 μl (1.0 μl)
× 10 ^-4 mol / mol: based on bisphenol A bismethyl carbonate). Argon replacement 5
After the repetition, the reaction was set in a 200 ° C. oil bath and reacted for 1 hour with stirring. After the reaction, the product was analyzed using liquid chromatography, and the concentration of the formed dimer and oligomer was determined. Further, the product was adjusted to an 8% by weight methylene chloride solution, and YI (yellow index) was measured. Table 1 shows the results. In the method of the present invention, it is evident from the analysis by liquid chromatography that the aromatic polycarbonate of 7,8-mer was obtained by the reaction for about 1 hour, and further, a solution in which the obtained oligomer was dissolved When the degree of coloring was observed, it was slightly colored.

Example 2 A reaction was performed in the same manner as in Example 1 except that the catalyst was used in place of tetramethylammonium hydroxide, and the product was evaluated. Table 1 shows the results.

Comparative Example 1 Example 1 was the same as Example 1 except that dibutyltin dimethoxide was used as a catalyst.

Comparative Example 2 The same as Example 1 except that nothing was added as a catalyst. Table 1 shows the results.

[0031]

[Table 1]

Example 3 A 20 ml glass test tube was filled with 0.34 g (1.0 mmo) of bisphenol A bismethyl carbonate.
1), 1 microliter of a 0.01 M acetone solution of tetrabutylammonium acetate was added. After repeating the replacement with argon five times, the mixture was set in a 300 ° C. block heater and reacted for 4 hours while stirring at normal pressure. After the reaction, the viscosity average molecular weight (Mv) and ¹ H-NMR
To determine the number average molecular weight (Mn). Further, the product was adjusted to an 8% by weight methylene chloride solution, and YI (yellow index) was measured. Table 2 shows the results. In addition, the intrinsic viscosity [η] is first determined, and then the formula [η] =
Mv was obtained using 1.23 × 10 ⁻⁵ × Mv ^0.83, and Table 2 was obtained.
It was shown to.

Comparative Examples 3 to 5 The same procedures as in Example 3 were carried out except that the catalyst and the reaction time were changed as shown in Table 2.

[0034]

[Table 2]

[0035]

According to the method of the present invention for producing a polycarbonate using a quaternary ammonium salt as a catalyst, an aromatic polycarbonate having extremely little color deterioration and excellent quality equivalent to that of a non-catalyst product can be produced as compared with an organotin catalyst. it can.

Claims (3)

[Claims] 1. A process for producing an aromatic polycarbonate, wherein a bisalkyl carbonate of an aromatic dihydroxy compound represented by the formula (A) is used as a raw material and a quaternary ammonium salt represented by the formula (B) is self-condensed as a catalyst. . Embedded image (Wherein R ¹ and R ² are an alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbon atoms, which may be the same or different from each other. Z is a divalent aromatic It is a residue.) (Wherein R ¹¹ , R ¹² , R ¹³ and R ¹⁴ have 1 to 3 carbon atoms)
0 alkyl group or cycloalkyl group, which may be the same or different from each other. X is a halogen atom, a hydroxyl group, an acetyl group, a phenoxy group or an alkoxy group. ) 2. The method according to claim 1, wherein the quaternary ammonium salt used as a catalyst is tetrabutylammonium acetate. As the bis-alkyl carbonates wherein the aromatic dihydroxy compound represented by formula (A), R ¹ and R
^The method for producing an aromatic polycarbonate according to claim 1 or 2, wherein a raw material wherein ² is a methyl group and the aromatic dihydroxy compound is bisphenol A is used.