JP3530706B2 - Method for producing aromatic polycarbonate - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polycarbonate by a transesterification method. More specifically, the present invention relates to a method for producing an aromatic polycarbonate having an improved heat resistance and a hue by a melt polycondensation reaction from an aromatic dihydroxy compound and a carbonic acid diester.

[0002]

2. Description of the Related Art Aromatic polycarbonates have recently been used as engineering plastics having excellent mechanical properties such as impact resistance, heat resistance, and transparency, as carbonated beverage bottles, electronic substrates (CD substrates), transfer belts. It is widely used in many fields such as electronic equipment housings. As a method for producing this aromatic polycarbonate, a so-called phosgene method in which an aromatic dihydroxy compound such as bisphenol and phosgene are reacted by an interfacial polycondensation method has been industrialized. However, this phosgene method requires the use of phosgene that is harmful to the human body, the problem of contamination of the generated polymer with sodium chloride, which is a large amount of by-product, and waste liquid treatment problems, and the hygiene of methylene chloride that is usually used as a reaction solvent. Concerns about atmospheric environmental problems,
Many problems have been pointed out, and a large amount of equipment cost is required for hygiene and environmental measures.

On the other hand, a method of obtaining an aromatic polycarbonate by transesterification between an aromatic dihydroxy compound such as bisphenol and a carbonic acid diester compound such as diphenyl has long been known as a so-called melting method or non-phosgene method. The non-phosgene method is said to be advantageous in that it does not have the various problems of the phosgene method as described above and can produce an aromatic polycarbonate more inexpensively. However, in the method for producing an aromatic polycarbonate by the non-phosgene method of reacting bisphenol A and diphenyl carbonate, generally,
Compared to the aromatic polycarbonate obtained by the phosgene method using bisphenol A / phosgene / end stopper, etc., the content of hydroxyl groups at the polymer end is large, and due to the influence of the catalyst residue used in the nonphosgene method, etc. The heat resistance and hue of the obtained aromatic polycarbonate are generally inferior to those of the aromatic polycarbonate obtained by the phosgene method.

An example of the production of aromatic polycarbonate by the non-phosgene method is, for example, JP-A-8-34849.
In the publication, when a polycarbonate is produced by melt polycondensation of an aromatic dihydroxy compound and a carbonic acid diester, 1 mol of the aromatic dihydroxy compound is added to
(A) An aliphatic amine having 24 to 60 carbon atoms is added to 10 ⁻⁶ to 10
^-1 molar amount and (b) an alkali metal compound and /
Alternatively, an alkaline earth metal compound is added to 5 × 10 ⁻⁸ to 8 × 10.
-Used in an amount of ^-7 mol, the first-step reaction was carried out under atmospheric pressure at 80-2.
50 ° C., preferably 100 to 230 ° C., more preferably 120 to 190 ° C., 5 hours or less, preferably 4
Both are reacted for not more than 3 hours, more preferably not more than 3 hours, and then the reaction temperature is raised while reducing the pressure of the reaction system. Finally, the aromatic dihydroxy compound and the carbonic acid are carbonated at 240 to 320 ° C. at 5 mmHg or less, preferably 1 mmHg or less. A polycondensation reaction with a diester is carried out, and the resulting reaction product contains (b) an alkali metal compound and / or an alkaline earth metal compound in an amount of 1 to 10 times the molar amount of the specific sulfonic acid compound and a further specific epoxy compound. Methods of adding compounds are described.

Further, in JP-A-8-113637, when a polycarbonate is produced from a dihydroxy compound and a carbonic acid diester, the [first step] temperature is 1
00 to 280 ° C, pressure from 10 torr to 5 kg / cm
² G range, preferably temperature 150-250 ° C., pressure 20 torr to 2 kg / cm ² G range, particularly preferably temperature 170-240 ° C., pressure 100 torr.
To 0 kg / cm ² G, the temperature and pressure are controlled to carry out the transesterification reaction, and the intrinsic viscosity [η] is 0.3 dl.
/ G or less, the terminal fraction of the aryl or alkyl carbonate terminal is in the range of 20 to 80 mol% to produce a polycarbonate prepolymer, and then the [second step] temperature is 20.
In the range of 0 to 350 ° C. and the pressure of 500 to 0.1 torr, the polycarbonate prepolymer obtained in the first step has a limiting viscosity [η] of 0.3 to 10 using a high viscosity-compatible reactor.
A method for obtaining a polycarbonate by allowing the reaction to proceed up to a range of 2 dl / g is described.

Further, in JP-A-8-239464, in producing a low-branched polycarbonate by carrying out melt transesterification of bisphenols and carbonic acid diaryl esters, 1 mol of bisphenols is added in the first step. Using a nitrogen or phosphorus base as a catalyst in an amount of 10 ^-2 to 10 ^-8 mol and at a temperature of 100 to 300 ° C., preferably 150 to 280 ° C. from atmospheric pressure to 0.5 mbar, preferably 500 to 1 mbar. Is applied to distill away monophenols to produce an oligocarbonate having an OH end group content of 10% or more and 35% or less as an intermediate, and then, in the second step, to 1 mol of bisphenols. 10 ^-4 to 10 ^-8 mol, particularly preferably 1
An alkali metal salt or an alkaline earth metal salt is added to the oligocarbonate in an amount of 0 ^-5 to 10 ^-7 mol to give 500
~ 250 mbar under pressure of 0.01 mbar
400 ° C., preferably 275 to 360 ° C., especially 280 to 32
A reaction vessel for high viscosity at a temperature of 0 ° C., particularly a screw mixer such as a ZSK twin-screw kneader is used, and preferably 1
Described is a method for producing a high-viscosity polycarbonate which is carried out within a short time, preferably within 30 minutes, particularly preferably within 15 minutes, and particularly within 10 minutes.

Thus, in the production of aromatic polycarbonate by the non-phosgene method (transesterification method),
In order to obtain high-molecular weight polycarbonate, we are conducting various studies on specific catalysts, reactors, and control methods for complicated reaction conditions. However, it is difficult to say that the conventional transesterification method has still yielded a sufficiently high-molecular-weight aromatic polycarbonate excellent in hue and thermal stability.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to obtain excellent hue stability even when the above-mentioned transesterification polycondensation method (non-phosgene method) is used, and there is little change in hue during heating and melting at the time of molding and the like. Another object of the present invention is to provide a method for producing an improved high molecular weight aromatic polycarbonate.

[0009]

That is, the present invention provides a method for producing an aromatic polycarbonate by melt polycondensation of an aromatic dihydroxy compound and a carbonic acid diester compound by a transesterification reaction, wherein an alkali metal compound is used as a transesterification reaction catalyst. (A) is used in an amount of 1 × 10 ⁻¹⁰ to 1 × 10 ⁻⁶ mol based on 1 mol of the aromatic dihydroxy compound, and the melt polycondensation reaction is carried out in two or more multi-stage steps. Further, it comprises a plurality of reaction steps of two or more, and in these reaction steps, the following mathematical formula (1):

[0010]

Ln P ≧ [−7428.3 / (T + 273)] + 19.6 (1) [wherein P represents reaction pressure (Torr) and T represents reaction temperature (° C.)]

The theoretical production amount of the monohydroxy compound, which is a by-product of the reaction under a temperature-pressure condition satisfying the above condition, is 40%.
% Or more is removed to the outside of the reaction system in the one reaction step or a plurality of reaction steps, and then the temperature of the reaction system is further raised and the pressure is reduced, and the remaining monohydroxy compound by-product is removed from the reaction system. To finally complete the melt polycondensation reaction at 260 ° C. to 330 ° C. under reduced pressure to obtain a viscosity average molecular weight (Mv) of 10,0.
The present invention provides a method for producing an aromatic polycarbonate, which comprises obtaining an aromatic polycarbonate of from 0 to 60,000.

Furthermore, in the present invention, the above-mentioned melt polycondensation reaction is carried out in a multi-step process of two or more steps, and in at least one reaction step of the first step, the temperature-pressure which satisfies the above mathematical expression (1) is satisfied. By removing 40% or more of the theoretically produced monohydroxy compound by reaction under the conditions out of the reaction system, the temperature of the reaction system is further raised and depressurized in the second and subsequent steps. By-product monohydroxy compound is removed to the outside of the reaction system, and finally 260 ° C to 330 ° C.
The present invention provides a method for producing an aromatic polycarbonate as described above, which comprises completing the melt polycondensation reaction under reduced pressure at a temperature of ° C.

Furthermore, in the present invention, the first step further comprises a plurality of reaction steps of two or more, and in the reaction step, the reaction is carried out under a temperature-pressure condition satisfying the above mathematical expression (1), A method for producing an aromatic polycarbonate as described above, characterized in that 40% or more of the theoretical production amount of a by-produced monohydroxy compound is removed to the outside of the reaction system in the one reaction step or a plurality of reaction steps. It is provided. Also, the steps after the second stage may be performed in a plurality of steps.

Furthermore, the present invention provides a method for producing an aromatic polycarbonate as described above, characterized in that a quaternary phosphonium salt (b) is used in addition to the alkali metal compound (a) as a transesterification reaction catalyst. It is provided.

Furthermore, in the present invention, the molar ratio of the alkali metal compound (a) to the quaternary phosphonium salt (b) [(a):
(B)] is 10 ⁻⁶ : 1 to 1: 1 and a method for producing the aromatic polycarbonate described above is provided.

[0016]

[Function] Uses a transesterification catalyst composed of an alkali metal compound, and has a sufficiently high molecular weight with a small amount of catalyst used, without using complicated reaction condition control or a special reactor, and has excellent hue and heat resistance. An aromatic polycarbonate is obtained.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Aromatic Dihydroxy Compound The aromatic dihydroxy compound used in the production of the present invention is a compound represented by the general formula (1).

[0018]

[Chemical 1]

(In the formula, A is a single bond, a substituted or unsubstituted linear, branched or cyclic divalent hydrocarbon group having 1 to 15 carbon atoms, and -O-, -S-, -CO. -, -SO-, -S
It is selected from the group consisting of divalent groups represented by O ₂ —, X and Y are the same or different from each other, and are selected from halogen or a hydrocarbon group having 1 to 6 carbon atoms. And p and q are integers of 0-2. )

Some typical examples of the aromatic dihydroxy compound represented by the above general formula (1) are, for example, bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane,
2,2-bis (4-hydroxy-3-t-butylphenyl) propane, 2,2-bis (4-hydroxy-3,5
-Dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 4,
4-bis (4-hydroxyphenyl) heptane, 1,1
-Bisphenol such as bis (4-hydroxyphenyl) cyclohexane; 4,4'-dihydroxybiphenyl,
Biphenols such as 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl; bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) ether , Bis (4-hydroxyphenyl) ketone, and the like. Of these, 2,2-bis (4-hydroxyphenyl) propane is preferable.

Two or more kinds of these compounds may be used in combination (copolymer), and when a branched aromatic polycarbonate is to be produced, a small amount of trivalent or higher polyhydric phenol is copolymerized. You can also Further, for the purpose of further improving the thermal stability and hydrolysis resistance of the aromatic polycarbonate produced, pt-butylphenol, pt-octylphenol, pt-octylphenol and pt-octylphenol are used for the purpose of sealing the hydroxyl terminal. Monohydric phenols such as millphenol can also be used.

Carbonic Acid Diester Compound As the carbonic acid diester compound used in the present invention, there are dimethyl carbonate and diethyl carbonate as typical examples of the aliphatic carbonic acid diester, and the aromatic carbonic acid diester represented by the general formula (2). There are some compounds.

[0023]

[Chemical 2]

(In the formula, R ¹ and R ² each independently represent an alkyl group having 1 to 10 carbon atoms or an alkoxy group, and m and n are integers of 0 to 2.) Formula (2 Examples of the carbonic acid diester compound represented by (4) include diphenyl carbonate, ditolyl carbonate, dixylyl carbonate, bisbutylphenyl carbonate, bisnonylphenyl carbonate, bismethoxyphenyl carbonate, and bisbutoxyphenyl carbonate. Among these, diphenyl carbonate is preferable. These carbonic acid diester compounds are generally used in excess with respect to 1 mol of the aromatic dihydroxy compound, and are used in an amount of 1.01 to 1.30 mol, preferably 1.02 to 1.20 mol. Is desirable.

Transesterification Reaction Catalyst In the present invention, an alkali metal compound (a) is used as the transesterification reaction catalyst. Also, in combination with this, the quaternary phosphonium salt compound (b) can be used. As the alkali metal compound (a), lithium,
Inorganic alkali metal compounds such as sodium, potassium, rubidium and cesium hydroxides, carbonates, hydrogen carbonate compounds, alcoholates with alcohols, phenolates with phenols, and organic alkali metals such as salts with organic carboxylic acids There are compounds, etc. Among these alkali metal compounds, a cesium compound is preferable from the viewpoint of improving the heat resistance of the obtained aromatic polycarbonate and a hue aspect, and most preferably cesium carbonate, cesium hydrogen carbonate, and cesium hydroxide.

The amount of the alkali metal compound (a) used is smaller than that in the conventional method, and it is 1 × 10 ^-10 per 1 mol of the aromatic dihydroxy compound used as a raw material.
To 1 × 10 ⁻⁶ mol, preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻⁷
Used in molar amounts. When the alkali metal compound is introduced into the reaction system as an aqueous solution of the alkali metal compound, the amount of water used is the aromatic dihydroxy compound 1 as the raw material.
The amount is 10 ⁻⁶ to 1 mol, preferably 10 ⁻⁴ to 1 mol.
An amount of 1 mol.

If the amount of the alkali metal compound (a) used is more than the above range, a gelled polymer is liable to be generated and an undesired side reaction is liable to occur, resulting in a heat resistance and a hue of the aromatic polycarbonate obtained. It is not preferable because it deteriorates and, in combination with the influence of the catalyst residue, deteriorates the quality at the time of molding and under the environmental conditions of use. If the amount of the catalyst used is too small, it will be difficult to obtain a high molecular weight aromatic polycarbonate having sufficient mechanical strength.

In the present invention, it is also preferable to use the quaternary phosphonium salt compound (b) together with the above-mentioned alkali metal compound (a) as a catalyst. Such a quaternary phosphonium salt compound (b) has the following general formula (3):

[0029]

[Chemical 3]

(In the formula, R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl or a cycloalkyl group, and X ^{r −} is a carbonate ion. , A phosphate ion, a tetrahydroxyboron ion, a sulfate ion, or a sulfite ion, and r represents its valence).

Specific examples of such a quaternary phosphonium salt compound (b) include tetraethylphosphonium carbonate, tetraethylphosphonium phosphate, tetraethylphosphonium tetrahydroxyborate, tetrabutylphosphonium carbonate, tetrabutylphosphonium phosphate, tetrabutylphosphonium tetra. Hydroxyborate, tetraphenylphosphonium carbonate, tetraphenylphosphonium phosphate, tetraphenylphosphonium tetrahydroxyborate, methyltriphenylphosphonium carbonate, methyltriphenylphosphonium phosphate, methyltriphenylphosphonium tetrahydroxyborate, allyltriphenylphosphonium carbonate, phosphoric acid Allyltriphenylphosphonium, allyltriphenylphosphonium tetrahydroxyborate , Butyltriphenylphosphonium carbonate, butyltriphenylphosphonium phosphate, butyltriphenylphosphonium tetrahydroxyborate, hexyltriphenylphosphonium carbonate, hexyltriphenylphosphonium phosphate, hexyltriphenylphosphonium tetrahydroxyborate, 4-carboxybutyltricarbonate Phenylphosphonium, 4-carboxybutyltriphenylphosphonium phosphate, 4
-Carboxybutyltriphenylphosphonium tetrahydroxyborate, 2-dimethylaminoethyltriphenylphosphonium carbonate, 2-dimethylaminoethyltriphenylphosphonium phosphate, 2-dimethylaminoethyltriphenylphosphonium tetrahydroxyborate, tetrakis (hydroxymethyl) phosphonium carbonate , Tetrakis (hydroxymethyl) phosphonium phosphate, tetrakis (hydroxymethyl) phosphonium tetrahydroxyborate, tetraethylphosphonium sulfate, tetraethylphosphonium sulfite, tetrabutylphosphonium sulfate, tetrabutylphosphonium sulfite, tetraphenylphosphonium sulfate, tetraphenylphosphonium sulfite, tetraphenylphosphonium sulfite, methyl sulfate Triphenylphosphonium,
Methyl triphenylphosphonium sulfite, allyltriphenylphosphonium phosphate, allyltriphenylphosphonium sulfite, butyltriphenylphosphonium sulfate,
Butyl triphenyl phosphonium sulfite, hexyl triphenyl phosphonium sulfate, hexyl triphenyl phosphonium sulfite, 4-carboxybutyl triphenyl phosphonium sulfate, 4-carboxybutyl triphenyl phosphonium sulfite, 2-dimethylaminoethyl triphenyl phosphonium sulfate, 2-dimethyl sulfite 2-dimethyl Aminoethyltriphenylphosphonium, tetrakis (hydroxymethyl) phosphonium sulfate, tetrakis (hydroxymethyl) phosphonium sulfite, and the like. Among these compounds, tetraethylphosphonium carbonate, tetraethylphosphonium tetrahydroxyborate, tetrabutylphosphonium carbonate, tetrabutylphosphonium tetrahydroxyborate, tetraethylphosphonium sulfate, and tetrabutylphosphonium sulfate are preferable because they give a higher molecular weight aromatic polycarbonate.

The amount of the quaternary phosphonium salt compound (b) used is the aromatic dihydroxy compound 1 used as a raw material.
1 × 10 ⁻⁸ to 1 × 10 ⁻⁴ mol, preferably 5 × 10 ^{−7 to} 5 × 10 ⁻⁵ mol, and particularly preferably 1 × 10 4.
Used in an amount of ^-7 to 1 x 10 ^-5 .

The molar ratio [(a) :( b)] of the alkali metal compound (a) and the quaternary phosphonium salt compound (b) is 1
It is preferably 0 ⁻⁶ : 1 to 1: 1. Thus, in the amounts used as described above, (a) an alkali metal compound and (b)
A catalyst in combination with a quaternary phosphonium salt compound is preferable because it allows the melt polycondensation reaction to proceed at a sufficient rate to generate a high-molecular weight polycarbonate with high polymerization activity.

Melt Polycondensation In the transesterification method melt polycondensation method of the present invention, in at least one reaction step, the above formula (1):

[0035]

Ln P ≧ [−7428.3 / (T + 273)] + 19.6 (1) [wherein P represents reaction pressure (Torr) and T represents reaction temperature (° C.)]

The theoretical production amount of the monohydroxy compound, which is a by-product of the reaction under a temperature-pressure condition satisfying the above condition, is 40
It can be carried out by a conventionally known melt polycondensation method of an aromatic polycarbonate, except that the control is performed so as to remove at least 100% from the reaction system.

That is, using the above raw materials, the monohydroxy compound by-produced by the transesterification reaction under heating / normal pressure (or pressurization) and reduced pressure is removed to the outside of the reaction system by the suction distillation method, and the melt weight is removed. Conduct condensation. The reaction is generally carried out in a multi-step process of two or more steps, and the reaction in the first step is controlled by the reaction conditions satisfying the above mathematical expression (1).

Specifically, first, in the first step, the raw material and the catalyst are mixed, and the temperature is set to 100 at an inert gas atmosphere.
To 260 ° C., preferably 150 to 250 ° C., at least one step or more in a condition range (conditions satisfying the above mathematical formula (1)) from pressurized or normal pressure to 221 Torr, and a by-produced monohydroxy compound is reacted. By removing from the polymer, transesterification, formation of a low molecular weight oligomer and chain extension reaction thereof proceed to obtain a polycarbonate prepolymer having a viscosity average molecular weight (Mv) of 500 to 5,000. At this time, it is an essential condition of the present invention that the by-produced monohydroxy compound is distilled up to 40% or more of the theoretical production amount. When carrying out the reaction continuously, the number of reaction steps in the first stage in this condition range is preferably 1 to 3. Here, the step can be considered as one step of a multi-tank reaction which is usually adopted for melt polycondensation of an aromatic polycarbonate. Alternatively, it means a reaction under the condition that the reaction temperature and / or the reaction pressure are changed.

In the reaction after the second step, the temperature is 240 to 300 ° C. in order to further extend the chain length of the polycarbonate prepolymer to obtain a higher molecular weight (viscosity average molecular weight 10,000 to 60,000). Decompression degree is 220 ~
The temperature is gradually increased in the range of 1 Torr to further remove mainly monohydroxy compounds and carbonic acid diesters from the reaction system, and finally the temperature is 260 to 330 ° C.
A high molecular weight polycarbonate is obtained by reducing the pressure to rr or less. When carrying out the reaction continuously, it is preferable to carry out in a plurality of reaction steps.

The reaction time in each step can be appropriately determined depending on the amount of the monohydroxy compound distilled out in the first step and the degree of progress of the reaction in the second and subsequent steps, but from the viewpoint of the hue of the obtained polymer. It is preferably 0.5 to 5 hours in the first stage and 0.5 to 4 hours in the second and subsequent stages. The monohydroxy compound by-produced in this reaction is an aliphatic alcohol when the starting carbonic acid diester compound is an aliphatic carbonic acid diester, and a phenolic compound when the starting carbonic acid diester compound is an aromatic diester.

The theoretical production amount of the by-produced monohydroxy compound defined in the present invention is an amount corresponding to twice the molar amount of the aromatic dihydroxy compound used. In the first step, it is necessary to control the reaction conditions so that the by-produced monohydroxy compound is removed to the outside of the reaction system by 40% or more of the theoretical amount. The distillate amount of the monohydroxy compound can be known by measuring the amount stored in the condenser. If the removal amount of the by-produced monohydroxy compound in the first step is less than 40%, only the low molecular weight aromatic polycarbonate can be produced even when the obtained polycarbonate prepolymer is subjected to the reaction in the second step and thereafter.

If the first-step reaction is carried out under reaction conditions that do not satisfy the mathematical expression (1), the carbonic acid diester compound or the like, which is a part of the raw material, is distilled off, and the transesterification reaction becomes difficult. .

The present invention can be carried out in either a batch system or a continuous system, and various apparatuses can be used. When the reaction is carried out continuously, the same type or different type of reaction apparatus is usually used for each reaction condition according to each reaction step. The structure of the reaction apparatus is not particularly limited, however, the viscosity is remarkably increased in the latter stage of the reaction, and therefore, a high-viscosity stirring function is preferable.

An example of a continuous reaction apparatus that can be preferably used in the present invention is as shown in FIG. In FIG. 1, five polymerization tanks are installed in series.
In the figure, 1 is a raw material introduction pipe, 2 is a transesterification catalyst introduction pipe,
3 is a by-product discharge pipe, 4 4 ', 4'', and 4''' are vertical polymerization tanks, 5 5 ', 5''are Maxblend stirring blades,
6 is a double helical ribbon wing. Further, 7 is a schematic horizontal sectional view of a horizontal polymerization tank, 8 and 9 are lattice blades, 10 is a first prepolymer, 11 is a second prepolymer, and 12 is a third prepolymer.
Prepolymer, 13 is the fourth prepolymer, and 14 is the final product polymer.

The aromatic polycarbonate obtained by the production method of the present invention includes a catalyst stabilizer, a heat resistance stabilizer, an ultraviolet absorber, a release agent, an antistatic agent, a slip agent, an antiblocking agent, a lubricant and an antifogging agent. Agent, colorant, fluidity improver,
Additives such as an organic reinforcing filler and an inorganic reinforcing filler can be blended and used. Such an additive can be added to the aromatic polycarbonate in a molten state, or the aromatic polycarbonate once pelletized can be remelted and added to this. The remelting is preferably performed in an inert gas atmosphere. In addition, other resins such as ethylene-vinyl acetate copolymer, polyamide, polystyrene, acrylonitrile
It can also be used by blending with a butadiene / styrene copolymer, polyester, polypropylene or the like.

[0046]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The aromatic polycarbonate obtained was analyzed by the following measuring method. (1) Viscosity average molecular weight (Mv) The intrinsic viscosity [η] at 20 ° C in methylene chloride was measured using an Ubbelohde viscometer, and the viscosity average molecular weight (Mv) was determined from the following formula. [Η] = 1.23 × 10 ⁻⁴ × (Mv) ^0.83 (2) Solution hue 16.7% methylene chloride solution with a diameter of 25 mm and a height of 55
The tristimulus value XYZ, which is the absolute value of the color, is measured with a color tester (SC-1-CH manufactured by Suga Test Instruments Co., Ltd.) in a mm cell made of glass, which is an index of yellowness according to the following relational expression. The Y1 value was calculated. YI = (100 / Y) × (1.28X-1.96Z) The larger the YI value, the more the coloring. (3) Using a sheet hue injection molding machine J100SS-2 (manufactured by Japan Steel Works), a square sheet having a thickness of 3 mm, a length of 100 mm and a width of 100 mm is injected under the conditions of a barrel temperature of 280 ° C. and a mold temperature of 90 ° C. Molded. About injection molded sheet, color tester (SC-1-CH manufactured by Suga Test Instruments Co., Ltd.)
Then, the tristimulus value XYZ which is the absolute value of the color was measured, and the YI value which is an index of the yellowness was calculated by the following relational expression. YI = (100 / Y) × (1.28X-1.96Z) The larger the YI value, the more the coloring. (4) Melt stability The solution hue after heating and melting at 360 ° C. for 1 hour under a nitrogen stream was measured by the method of (2). (5) Residence stability Using an injection molding machine IS55 (manufactured by Toshiba Machine Co., Ltd.), aromatic polycarbonate was retained in the barrel for 10 minutes at a barrel temperature of 360 ° C., and then a thickness of 3 was obtained under a mold temperature of 80 ° C.
mm, 65 mm long, 65 mm wide square sheet was injection molded. This retention molding was continuously performed 5 times, and the hue of the fifth molded sheet was measured by the method (3).

Example 1 First-stage bisphenol A 182.6 g (0.8 mol), diphenyl carbonate 188.5 g (0.88 mol), and a 0.18% cesium carbonate aqueous solution 50 μl (carbonic acid as a transesterification catalyst) Cesium (2.8 × 10 ⁻⁷ mol) was put into a glass reaction vessel with an internal volume of 500 ml equipped with a stirrer and a distillation device, and the inside of the reaction vessel was replaced with nitrogen gas, and then the contents were heated at 210 ° C. under a nitrogen gas atmosphere. Was dissolved. After the contents were completely dissolved, this state was maintained at 210 ° C. under normal pressure for 1 hour. Next, the pressure in the reactor was gradually lowered to 100 Torr to distill phenol, and this state was maintained until the distillate amount of phenol was 43% of the theoretical production amount (150.4 g). The holding time at 210 ° C. and 100 Torr was 1 hour. Second stage After that, the reaction temperature was raised to 240 ° C., the pressure in the reactor was gradually lowered to 15 Torr, and the reaction was continued for 1 hour in this state. Next, the reaction temperature was further raised to 270 ° C., the pressure in the reactor was lowered to 0.5 Torr, and the reaction was continued for 1 hour to obtain about 200 g of a polymer (aromatic polycarbonate). Table 2 shows the analysis results of the obtained polycarbonate.

Example 2 The amount of cesium carbonate used as a transesterification reaction catalyst was 4.0 × 10 ^-7 mol (0.26% cesium carbonate aqueous solution 50 μl), 210 ° C., 100 To.
Distill the amount of phenol in the reaction under the condition of rr to 45
% (Required time 1 hour) except that the polycarbonate was obtained under the same conditions and methods as in Example 1. Table 2 shows the analysis results of the obtained polycarbonate.

Example 3 The amount of cesium carbonate used as a transesterification reaction catalyst was 8.0 × 10 ⁻⁷ mol (0.52% cesium carbonate aqueous solution 50 μl), 210 ° C., 100 To.
The phenol distillate amount in the reaction under the condition of rr was 53
% (Required time 1 hour) except that the polycarbonate was obtained under the same conditions and methods as in Example 1. Table 2 shows the analysis results of the obtained polycarbonate.

(Example 4) Bisphenol A 182.6
g (0.8 mol), diphenyl carbonate 188.5 g
(0.88 mol), and 50 μl of a 0.18% cesium carbonate aqueous solution (cesium carbonate 2.8 × 10 ⁻⁷ mol) as a transesterification reaction catalyst having an internal volume of 500 ml, a glass reaction container equipped with a stirrer and a distillation device. The contents were melted at 220 ° C. in a nitrogen gas atmosphere after the reaction vessel was replaced with nitrogen gas. After the contents were completely dissolved, this state was maintained at 220 ° C. under normal pressure for 1 hour. Next, the pressure in the reactor was gradually lowered to 100 Torr to distill phenol, and the distillate amount of phenol was theoretically produced (150.4 g).
This state was maintained until it reached 55%. 220 ° C,
The retention time at 100 Torr was 1 hour. Thereafter, the reaction temperature was raised to 240 ° C., the pressure in the reactor was gradually lowered to 15 Torr, and the reaction was continued for 1 hour in this state. Next, the reaction temperature was further raised to 270 ° C., the pressure in the reactor was lowered to 0.5 Torr, and the reaction was continued for 1 hour to obtain about 200 g of a polymer (aromatic polycarbonate). Table 2 shows the analysis results of the obtained polycarbonate.

(Comparative Example 1) Bisphenol A182.6
g (0.8 mol), diphenyl carbonate 188.5 g
(0.88 mol), and 50 μl of a 0.18% cesium carbonate aqueous solution (cesium carbonate 2.8 × 10 ⁻⁷ mol) as a transesterification reaction catalyst having an internal volume of 500 ml, a glass reaction container equipped with a stirrer and a distillation device. The contents were melted at 210 ° C. in a nitrogen gas atmosphere after the reaction vessel was replaced with nitrogen gas. After the contents were completely dissolved, this state was maintained at 210 ° C. under normal pressure for 1 hour. Next, the pressure in the reactor was gradually lowered to 100 Torr to distill phenol, and the distillate amount of phenol was theoretically produced (150.4 g).
This state was maintained until it reached 20%. 210 ℃,
The retention time at 100 Torr was 30 minutes. Then, the reaction temperature was raised to 240 ° C., the pressure in the reactor was gradually lowered to 15 Torr, and the reaction was continued for 1 hour in this state. Then, the reaction temperature was further raised to 270 ° C., the pressure in the reactor was lowered to 0.5 Torr, and the reaction was continued for 1 hour to obtain about 200 g of a polymer (aromatic polycarbonate). Table 2 shows the analysis results of the obtained polycarbonate.

Comparative Example 2 The amount of cesium carbonate used as a transesterification catalyst was 4.0 × 10 ^-7 mol (0.26% cesium carbonate aqueous solution 50 μl), 210 ° C., 100 To.
The amount of phenol distilled in the reaction under the condition of rr was 30
% (Required time 40 minutes) except that the polycarbonate was obtained under the same conditions and methods as in Example 1 except that the content was changed to 40%. Table 2 shows the analysis results of the obtained polycarbonate.

(Example 5) Bisphenol A 182.6
g (0.8 mol), diphenyl carbonate 188.5 g
(0.88 mol), and as a transesterification reaction catalyst, 50 μl of 0.052% cesium carbonate aqueous solution (cesium carbonate 0.8 × 10 ⁻⁷ mol) and Et ₄ PB (OH) ₄ (tetraethylphosphonium tetrahydroxyborate: this product) Was synthesized by acid-base reaction using tetraethylphosphonium hydroxide and boric acid.) 0.024 m
ol / liter aqueous solution 83 μl (2.0 × 10 ⁻⁶ mol)
Was placed in a glass reaction container with an internal volume of 500 ml equipped with a stirrer and a distillation device, the inside of the reaction container was replaced with nitrogen gas, and then the contents were dissolved at 210 ° C. in a nitrogen gas atmosphere. After the contents were completely dissolved, this state was maintained at 210 ° C. under normal pressure for 1 hour. Next, gradually increase the pressure in the reactor to 100 To
The phenol was distilled down to rr, and this state was maintained until the amount of phenol distilled out was 50% of the theoretical production amount (150.4 g). The holding time at 210 ° C. and 100 Torr was 1 hour. Then set the reaction temperature to 240
While raising the temperature to ℃, gradually increase the pressure in the reactor to 15 To
The temperature was lowered to rr, and the reaction was continued for 1 hour in this state. Next, the reaction temperature was further raised to 270 ° C., the pressure in the reactor was lowered to 0.5 Torr, and the reaction was continued for 1 hour to obtain about 200 g of a polymer (aromatic polycarbonate). Table 2 shows the analysis results of the obtained polycarbonate.

(Example 6) Bisphenol A 182.6
g (0.8 mol), diphenyl carbonate 188.5 g
(0.88 mol), and as a transesterification reaction catalyst, 50 μl of 0.052% cesium carbonate aqueous solution (cesium carbonate 0.8 × 10 ⁻⁷ mol) and Et ₄ PB (OH) ₄ (tetraethylphosphonium tetrahydroxyborate: this product) Was synthesized by acid-base reaction using tetraethylphosphonium hydroxide and boric acid.) 0.024 m
ol / liter aqueous solution 83 μl (2.0 × 10 ⁻⁶ mol)
Was placed in a glass reaction container with an internal volume of 500 ml equipped with a stirrer and a distillation device, the inside of the reaction container was replaced with nitrogen gas, and then the contents were dissolved at 210 ° C. in a nitrogen gas atmosphere. After the contents were completely dissolved and the internal temperature reached 210 ° C, the pressure in the reactor was gradually lowered to 100 Torr to distill phenol, and the distillate amount of phenol was the theoretical production amount (15
This state was maintained until it reached 45% of 0.4 g).
The holding time at 210 ° C. and 100 Torr was 1 hour. Thereafter, the reaction temperature was raised to 240 ° C., the pressure in the reactor was gradually lowered to 15 Torr, and the reaction was continued for 1 hour in this state. Then, the reaction temperature is further increased to 270.
While raising the temperature to ℃, the pressure inside the reactor is 0.5 Torr.
And the reaction was continued for 1 hour to obtain about 200 g of a polymer (aromatic polycarbonate). Table 2 shows the analysis results of the obtained polycarbonate.

Example 7 The amount of cesium carbonate used as one component of the transesterification reaction catalyst was 2.0 × 10 ⁻⁷ mol (50 μl of 0.13% cesium carbonate aqueous solution) and 21.
A polycarbonate was obtained under the same conditions and methods as in Example 6, except that the amount of phenol distilled out in the reaction under the conditions of 0 ° C. and 100 Torr was changed to 54% (required time: 1 hour). Table 2 shows the analysis results of the obtained polycarbonate.

Example 8 The amount of cesium carbonate used as one component of the transesterification reaction catalyst was 8.0 × 10 ⁻⁷ mol (50 μl of 0.52% cesium carbonate aqueous solution) and 21
A polycarbonate was obtained under the same conditions and methods as in Example 6, except that the amount of phenol distilled out in the reaction under the conditions of 0 ° C. and 100 Torr was changed to 60% (required time: 1 hour). Table 2 shows the analysis results of the obtained polycarbonate.

(Comparative Example 3) The same conditions and methods as in Example 5 were used except that the amount of phenol distilled out in the reaction under the conditions of 210 ° C. and 100 Torr was changed to 31% (required time: 45 minutes). To obtain a polycarbonate.
Table 2 shows the analysis results of the obtained polycarbonate.

(Comparative Example 4) The same conditions and methods as in Example 7 were used except that the amount of phenol distilled out in the reaction under the conditions of 210 ° C. and 100 Torr was changed to 35% (required time 40 minutes). To obtain a polycarbonate.
Table 2 shows the analysis results of the obtained polycarbonate.

[0059]

[Table 1]

[0060]

[Table 2]

(Example 9) In a nitrogen gas atmosphere, bisphenol A and diphenyl carbonate were mixed at a constant molar ratio (DPC / BPA = 1.045) to prepare a molten mixture, and the total flow rate was 403.27 mol / hour. Then, the MaxBlend blade shown in FIG. 1 is provided through the raw material introducing pipe, and the capacity is controlled to 210 ° C. under normal pressure and nitrogen atmosphere.
It is continuously fed into 0 liter of the first rigid stirring polymerization tank 5, and the liquid level is kept constant while controlling the valve opening provided in the polymer discharge line at the bottom of the tank so that the average residence time is 60 minutes. I kept it. At the same time when the supply of the above raw material mixture was started, 0.42 × 1 as a transesterification reaction catalyst
A 0 ^-3 % aqueous cesium carbonate solution was continuously supplied at a flow rate of 360 ml / hour (3.5 x 10 ^-7 mol with respect to 1 mol of bisphenol A), and the mixture was stirred at 200 rpm. The polymerization liquid discharged from the bottom of the tank was continuously stirred in the second, third, and fourth (second and third tanks: Maxblend blade, fourth tank: double-helical ribbon blade) with a capacity of 100 L, and was stirred. Also, the polymer (aromatic polycarbonate), which was continuously supplied to a horizontal polymerization tank having an internal capacity of 150 L equipped with a fifth lattice blade and was withdrawn from the polymer outlet at the bottom of the fifth polymerization tank, was devolatilized and cooled, and then pelletized. did. During this reaction,
The liquid level is controlled so that the average residence time of each of the second to fourth polymerization tanks is 60 minutes and the average residence time of the fifth polymerization tank is 90 minutes, and at the same time, the by-product phenol is distilled off. went. At this time, the amount of distillate from 3 shown in FIG. 1 was measured. The reaction conditions in each of the second to fifth polymerization tanks are the second
Polymerization tank (210 ° C, 100 Torr, 200 rpm)
(The reaction of the first stage was performed up to this point, and the amount of phenol distilled was 55% of the theoretical production amount (37.1 kg / hour)), the third polymerization tank (240 ° C, 15 Torr, 100 r
pm), 4th polymerization tank (280 ° C., 0.5 Torr, 40
rpm) at the fifth polymerization tank (285 ° C., 0.5 Torr,
At 10 rpm), conditions were set to high temperature, high vacuum, and low stirring speed as the reaction proceeded. Table 4 shows the analysis results of the obtained polycarbonate.

(Example 10) 36 ml of a 9.21 × 10 ^-3 % cesium carbonate aqueous solution was used as a transesterification catalyst.
/ H (5.0 x 10 for 1 mol of bisphenol A)
^-7 mol) was continuously supplied, and the reaction conditions of the fourth polymerization tank were changed to 270 ° C., 0.5 Torr, 40 rpm, and the reaction conditions of the fifth polymerization tank were changed to 280 ° C., 0.5 Torr, 10 rpm, respectively. Polycarbonate was obtained under the same conditions and methods as in Example 9. The amount of phenol distilled off in the first stage reaction was 6 of the theoretical amount (37.1 kg / hour).
It was 8%. Table 4 shows the analysis results of the obtained polycarbonate.

Example 11 The molar ratio of diphenyl carbonate to bisphenol A was 1.040 (DPC).
/ BPA) and the melt mixture prepared by
It is continuously supplied to the first polymerization tank at a flow rate of 2.29 mol / hour, and 1.84 × 10 ⁻² % cesium carbonate aqueous solution as a transesterification catalyst is 360 ml / hour (1.0 mol based on 1 mol of bisphenol A). Polycarbonate was obtained under the same conditions and methods as in Example 10, except that continuous feeding was performed at a flow rate of × 10 ^-6 mol). The amount of phenol distilled off in the first-step reaction was 73% of the theoretical production amount (37.1 kg / hour). Table 4 shows the analysis results of the obtained polycarbonate.

Comparative Example 5 A polycarbonate was obtained under the same conditions and methods as in Example 10, except that the liquid level was controlled so that the average residence time in the first and second polymerization tanks was 30 minutes. It was The amount of phenol distilled off in the first-step reaction was 35% of the theoretical production amount (37.1 kg / hour).
Table 4 shows the analysis results of the obtained polycarbonate.

Example 12 Cesium carbonate was 3.21 × 10 ⁻³ % as a transesterification catalyst, and Et ₄ PB was used.
200 ml / hour of the catalyst mixed aqueous solution prepared so that (OH) ₄ was 2.47 × 10 ⁻³ mol / liter (for 1 mol of bisphenol A, cesium carbonate was 1.0 × 1
0 ^-7 mol, and Et ₄ PB (OH) ₄ is 2.5 × 10 ^-6
Mol) continuously and the reaction condition of the fifth polymerization tank is 2
A polycarbonate was obtained under the same conditions and methods as in Example 9, except that the temperature was changed to 95 ° C., 0.5 Torr, and 10 rpm. The amount of phenol distilled off in the first-step reaction was 73% of the theoretical production amount (37.1 kg / hour). Table 4 shows the analysis results of the obtained polycarbonate.

Comparative Example 6 A polycarbonate was obtained under the same conditions and methods as in Example 12, except that the liquid level was controlled so that the average residence time in the first and second polymerization tanks was 30 minutes. It was The amount of phenol distilled off in the first-step reaction was 34% of the theoretical production amount (37.1 kg / hour).
Table 4 shows the analysis results of the obtained polycarbonate.

[0067]

[Table 3]

[0068]

[Table 4]

[0069]

According to the process for producing an aromatic polycarbonate of the present invention, it is possible to obtain a high molecular weight aromatic polycarbonate having excellent quality such as hue and heat resistance.

[Brief description of drawings]

FIG. 1 is a flow sheet diagram of a manufacturing method of the present invention.

[Explanation of symbols]

1 Raw material introduction pipe 2 catalyst introduction pipe 3 By-product discharge pipe 4 Vertical polymerization tank 5 stirring blades 7 Horizontal polymerization tank 10 Prepolymer 14 Final Product Polymer

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsushige Hayashi 2-4-16 Hinoei Higashihigashi, Yokkaichi-shi, Mie Mitsubishi Gas Chemical Co., Ltd. Yokkaichi Plant (72) Inventor Atsushi Hirashima 2 Honeihigashi, Yokkaichi-shi, Mie 4-16 No. Mitsubishi Gas Chemical Co., Ltd. Yokkaichi Plant (56) Reference JP-A-7-324128 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 64/00- 64/42

Claims (3)

(57) [Claims] 1. A method for producing an aromatic polycarbonate by melt polycondensation of an aromatic dihydroxy compound and a carbonic acid diester compound by a transesterification reaction, wherein an alkali metal compound (a) is used as a transesterification reaction catalyst for the aromatic dihydroxy compound 1. 1 × 10 ⁻¹⁰ per mole
~ 1 × 10 ^-6 mol is used, the melt polycondensation reaction is carried out in a multi-step process of two or more steps, the step of the first step further comprises two or more reaction steps, in these reaction steps, The following formula (1): ln P ≧ [−7428.3 / (T + 273)] + 19.6 (1) [wherein, P is reaction pressure (Torr), T is reaction temperature (° C.) Represent 40% or more of the theoretical production amount of the monohydroxy compound by-produced by the reaction under a temperature-pressure condition satisfying the above conditions is removed to the outside of the reaction system in the one reaction step or a plurality of reaction steps. The reaction system is further heated and decompressed to remove the remaining by-produced monohydroxy compound outside the reaction system, and finally the melt polycondensation reaction is completed under reduced pressure at 260 ° C. to 330 ° C. to obtain a viscosity average molecular weight ( Mv) 10,
A method for producing an aromatic polycarbonate, characterized in that 000 to 60,000 aromatic polycarbonate is obtained. 2. The method for producing an aromatic polycarbonate according to claim 1, wherein a quaternary phosphonium salt (b) is used in addition to the alkali metal compound (a) as a transesterification reaction catalyst. 3. The molar ratio [(a) :( b)] of the alkali metal compound (a) to the quaternary phosphonium salt (b) is 1.
0 ^-6: 1 to 1: characterized in that it is a 1, claim 1
Or the method for producing an aromatic polycarbonate described in 2.