JP2002241486A - Production method of aromatic-aliphatic copolymerized polycarbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for stably producing an aromatic-aliphatic copolymerized polycarbonate useful as an optical material and having an excellent hue. SOLUTION: The production method of an aromatic-aliphatic copolymerized polycarbonate comprises melt-polymerizing an aromatic carbonate diester, at least one aliphatic dihydroxy compound having an alicyclic structure and at least one aromatic dihydroxy compound in the presence of an alkali metal catalyst and/or an alkaline earth metal catalyst, where the molecular weight of the produced polymer is controlled by adjusting the operating temperature to not higher than 250 deg.C and the pressure to not higher than 133 Pa in the final polycondensation reactor.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method for producing a transparent aromatic-aliphatic copolymer polycarbonate having excellent impact strength, high refractive index and Abbe number, low photoelastic constant and excellent hue. The polycarbonate resin can be suitably used for optical materials such as various lenses, prisms, optical disk substrates, and optical fibers.

[0002]

2. Description of the Related Art A polycarbonate obtained by interfacially polymerizing an aromatic dihydroxy compound such as 2,2-bis (4-hydroxyphenyl) propane (hereinafter, referred to as BPA) and phosgene in the presence of an acid binder is: Because of its excellent mechanical properties such as impact resistance, and also excellent heat resistance and transparency, it is used as an optical material for various lenses, prisms, optical disk substrates, and the like. However, polycarbonate using only BPA as the aromatic dihydroxy compound has a large photoelastic constant and relatively low melt fluidity, resulting in a large birefringence of the molded product. Since the Abbe number indicating the degree of dispersion is as low as 30, and the balance between the refractive index and the Abbe number is poor, it has a drawback that it does not have sufficient performance to be widely used for applications such as optical recording materials and optical lenses. is there. For the purpose of solving the above-mentioned drawbacks of BPA-polycarbonate, a copolymer polycarbonate of BPA and tricyclo (5.2.1.0 ^2,6 ) decane dimethanol (hereinafter, referred to as TCDDM) has been proposed. Kaisho 64-662
No. 34). The aromatic-aliphatic copolymerized polycarbonate has excellent impact resistance and heat resistance, and furthermore, has a small photoelastic constant and a high Abbe number, so that it can be widely used as an optical material. However, the method for producing this copolymerized polycarbonate is as follows: (1) Bischloroformate of BPA and TCDDM or TCDDM and BP
A, (2) polycondensation of bischloroformate of TCDDM with BPA or BPA and TCDDM, (3) bischloroformate of BPA and TCDDM
Only the method of polycondensing a mixture of the above with bischloroformate and BPA and / or TCDDM. In the production of such a copolymer of an aliphatic dihydroxy compound and an aromatic dihydroxy compound, the production process is complicated by a two-stage reaction in which a bischloroformate of the dihydroxy compound is produced and then polycondensed with the dihydroxy compound. As a result, there is a disadvantage that the manufacturing cost is increased. As a method for producing polycarbonate, in addition to the phosgene method (chloroformate method),
There is known a transesterification method in which a carbonic acid diester and a dihydroxy compound are polycondensed in a molten state. This manufacturing method has a relatively simple manufacturing process and is an industrially useful method. However, the polycarbonate resin produced by this method has a problem that the quality of the obtained polycarbonate varies. In particular, in optical material applications requiring high quality, uniformity of quality is one of the important items, and it cannot be said that aromatic-aliphatic copolymer polycarbonate having uniform quality can be stably produced. Was.

When the aromatic-aliphatic copolymerized polycarbonate is produced by a transesterification reaction, it has been more difficult to control the polymer quality, especially the molecular weight of the produced polymer, to a predetermined value as compared with the phosgene method. For example, JP
In the publication No. 00-143792, the operating conditions of the late-stage polymerization reaction tank are performed at a temperature of 250 to 320 ° C. and a pressure of 10 to 0.1 hPa, and as the process proceeds to the subsequent stirring tank, the temperature is sequentially increased and the degree of vacuum is reduced. It shows how to lower the value,
The aromatic-aliphatic copolymerized polycarbonate is easily colored at a high temperature, and it is difficult to obtain a polymer having a colorless and transparent color tone under ordinary production conditions for an aromatic polycarbonate.

[0004]

SUMMARY OF THE INVENTION The present invention aims to solve the problems associated with the prior art as described above, and provides excellent impact resistance, heat resistance, high Abbe number and low photoelastic constant. It is an object of the present invention to provide a production method for obtaining the aromatic-aliphatic polycarbonate having excellent color tone with stable quality.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve these problems, and as a result, completed the present invention. That is, the present invention provides a method for melt-polymerizing an aromatic carbonic acid diester with at least one aliphatic dihydroxy compound having an alicyclic structure and at least one aromatic dihydroxy compound in the presence of an alkali metal and / or alkaline earth metal catalyst. In the method for producing an aromatic-aliphatic copolymerized polycarbonate, the operating temperature of the final polycondensation reactor is controlled to 250 ° C. or less, and the pressure is controlled to 133 Pa or less to control the molecular weight of the produced polymer, and to provide excellent hue and stability. A method for producing an aromatic-aliphatic copolymer polycarbonate characterized by producing a high-quality aromatic-aliphatic copolymer polycarbonate resin.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing an aromatic-aliphatic copolymer polycarbonate resin according to the present invention will be specifically described.

[0007] In a method for continuously producing an aromatic-aliphatic copolymerized polycarbonate by installing two or more reactors in series, the temperature and pressure of the final polycondensation reactor depend on the operating conditions of the produced polymer. Is controlled to a predetermined value,
A stable quality aromatic-aliphatic copolymer polycarbonate resin can be obtained. More specifically, the operating temperature of the final polycondensation reactor is 250 ° C. or less, preferably 245 ° C.
° C or less, operating pressure is 133 Pa or less, preferably 40 P
a, the stable quality of aromatic-
An aliphatic copolymer polycarbonate resin can be obtained.

When the molecular weight of the produced polymer is to be increased, it can be controlled by increasing the polymerization temperature. However, since the aromatic-aliphatic copolymer polycarbonate resin of the present invention tends to be colored at a high temperature, the operating pressure is high. It is preferable to control the molecular weight by lowering the molecular weight to 133 pa or less.

The aromatic carbonate diester used in the present invention is a compound represented by the following general formula (III).

[0010]

Embedded image

Wherein Ar is a monovalent aromatic group;
May be the same or different. )

The aromatic carbonic diester represented by the general formula (III) is, for example, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate, bispropylphenyl carbonate, bisoctylphenyl carbonate, bisnonylphenyl carbonate, bismethoxyphenyl Substituted diphenyl carbonates such as carbonate and bisethoxyphenyl carbonate are exemplified, but diphenyl carbonate is particularly preferred. The chlorine content is preferably 1 ppm or less. The aromatic carbonate diester is preferably used in an amount of 0.97 to 1.2 mol, particularly preferably 0.99 to 1.10 mol, per 1 mol of the total of the dihydroxy compound.

The aliphatic dihydroxy compound having an alicyclic structure used in the reaction of the present invention includes, for example, tricyclo (5.2.1.0 ^2,6 ) decanedimethanol, β,
β, β ′, β′-tetramethyl-2,4,8,10-tetraoxaspiro [5,5] undecane-3,9-diethanol (spiroglycol), pentacyclo [9.
2.1.1 ^3,9 . 0 ^2,10 . 0 ^4,8 ] pentadecanedimethanol, pentacyclo [9.2.1.1 ^4,7 . 0 ^2,10 . 0
^3,8 ] pentadecane dimethanol, 2,6-decalin dimethanol or 1,4-cyclohexane dimethanol. Of these, tricyclo (5.2.1.0 ^2,6 ) decanedimethanol is particularly preferred. As the dihydroxy compound having an alicyclic structure, a compound having a carbonyl group content of 1.0 mg / g or less, preferably 0.5 mg, and more preferably 0.1 mg or less in terms of KOH is used. Also,
It is preferable that the content of each of chlorine and metal ions is 1 ppm or less.

The aromatic dihydroxy compound used in the reaction of the present invention is a compound represented by the following general formula (IV).

[0015]

Embedded image

(In the above formula (IV), X is

Embedded image

Wherein R ₃ and R ₄ are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a phenyl group, and R ₃ and R ₄ may combine to form a ring. R
₁ and R ₂ are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or halogen, and R ₁ and R ₂ may be the same or different. Further, m and n represent the number of substituents and are integers of 0 to 4. )

Examples of the aromatic dihydroxy compound represented by the general formula (IV) include bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane, and 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 Bisphenols such as -hydroxy-3,5-dibromophenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane and 1,1-bis (4-hydroxyphenyl) cyclohexane;
4'-dihydroxydibiphenyl, 3,3 ', 5,5'
Biphenols such as -tetramethyl-4,4'-dihydroxybiphenyl; bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) Ether and bis (4-hydroxyphenyl) ketone. Among these, 1,1-bis (4-hydroxyphenyl) cyclohexane (hereinafter referred to as BPZ) is particularly preferred. Also,
The aromatic dihydroxy compound represented by the formula (IV) is
More than one kind can be used in combination.

As the polymerization catalyst, a basic compound is used. Examples of such a basic compound include an alkali metal compound, an alkaline earth metal compound, and a nitrogen-containing compound. These compounds can be used alone or in combination.

As the alkali metal compound, organic acid salts, inorganic acid salts, oxides, hydroxides, hydrides, and alcoholates of alkali metals are used. Cesium oxide, lithium hydroxide, sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, cesium acetate, lithium acetate, sodium stearate, potassium stearate , Cesium stearate,
Lithium stearate, sodium borohydride, lithium borohydride, sodium borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, hydrogen phosphate Dilithium, disodium phenylphosphate, dipotassium phenylphosphate, dilithium phenylphosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, phenol sodium salt, potassium salt, cesium salt , Lithium salts and the like are used.

Further, as the alkaline earth metal compound,
Alkaline earth metal organic acid salts, inorganic acid salts, oxides, hydroxides, hydrides, alcoholates and the like are used, specifically, calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, Calcium bicarbonate,
Barium bicarbonate, magnesium bicarbonate, strontium bicarbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate,
Calcium stearate, barium stearate, magnesium stearate, strontium stearate,
Are used.

As the nitrogen-containing compound, quaternary ammonium hydroxides, quaternary ammonium salts, amines and the like are used. Specifically, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutyl Ammonium hydroxides having alkyl, aryl, araryl groups and the like such as ammonium hydroxide and trimethylbenzylammonium hydroxide, tertiary amines such as trimethylamine, triethylamine, dimethylbenzylamine and triphenylamine, dimethylamine and diethylamine Primary amines such as secondary amine, methylamine and ethylamine; imidazoles such as 2-methylimidazole and 2-phenylimidazole; A, tetramethyl ammonium borohydride, tetrabutyl ammonium borohydride, tetrabutyl ammonium tetraphenylborate, basic salts such as tetramethylammonium tetraphenylborate and the like are used.

These catalysts are used in an amount of 10 ^-9 to 10 ^-3 mol, preferably 1 to 1 mol per total of the dihydroxy compound.
Used in an amount of 0 ^-7 to 10 ^-5 mol

In the aromatic-aliphatic copolymer polycarbonate of the present invention, the molar ratio of the structural unit (A) derived from the aromatic dihydroxy compound and the structural unit (B) derived from the alicyclic aliphatic dihydroxy compound used as a raw material is used. (A) /
(B) is preferably from 90/10 to 10/90, more preferably from 80/20 to 20/80. That is, when the molar ratio (A) / (B) of this structural unit is lower than 10/90, the heat resistance becomes poor, and
If it is higher than 10, the photoelastic constant, the water absorption and the like will increase, and the balance between the refractive index and the Abbe number will worsen, which is not preferable as an optical material.

The weight average molecular weight of the aromatic-aliphatic copolymer polycarbonate according to the present invention is from 20,000 to 20.
It is preferably 0.000, more preferably 4
It is between 000 and 100,000.

As a catalyst deactivator, for example, phosphoric acid,
Phosphorous acid, hypophosphorous acid, phenylphosphoric acid, phenylphosphine, phenylphosphinic acid, phenylphosphonic acid,
Diphenyl phosphate, diphenyl phosphite, diphenyl phosphine, diphenyl phosphine oxide,
Diphenyl phosphinic acid, monomethyl acid phosphate, monomethyl acid phosphite, dimethyl acid phosphate, dimethyl acid phosphite, monobutyl acid phosphate, monobutyl acid phosphite, dibutyl acid phosphate, dibutyl acid phosphite, monostearyl acid phosphate, distearyl acid Phosphorus-containing acidic compounds such as phosphate, p-toluenesulfonic acid, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, p-toluenesulfonic acid
-Propyl toluenesulfonate, butyl p-toluenesulfonate, pentyl p-toluenesulfonate, hexyl p-toluenesulfonate, octyl p-toluenesulfonate, phenyl p-toluenesulfonate, phenethyl p-toluenesulfonate, p- Aromatic sulfonic acid compounds such as naphthyl toluenesulfonate are exemplified.

The amount of the phosphorus-containing acidic compound or aromatic sulfonic acid compound to be added is 1/5 to 20 times the equivalent of neutralization with respect to the alkali metal and / or alkaline earth metal catalyst.
The amount is preferably 1/2 to 10 times the amount. If the amount is less than this, the desired effect cannot be obtained. If the amount is excessive, the heat resistance and mechanical properties decrease, which is not appropriate.

Further, aromatic sulfonate phosphonium salts can also be preferably used. For example, benzenesulfonic acid tetrabutylphosphonium salt, p-toluenesulfonic acid tetrabutylphosphonium salt, butylbenzenesulfonic acid tetrabutylphosphonium salt, octylbenzene Examples include tetrabutylphosphonium sulfonic acid salt, tetrabutylphosphonium dodecylbenzenesulfonic acid salt, tetramethylphosphonium dodecylbenzenesulfonic acid salt, tetraethylphosphonium dodecylbenzenesulfonic acid salt, and tetrahexylphosphonium dodecylbenzenesulfonic acid salt.

The amount of the phosphonium aromatic sulfonate added is from 1 to 300 ppm, preferably from 10 to 100 ppm, based on the aromatic-aliphatic copolymerized polycarbonate. If the amount is less than this, the desired effect cannot be obtained. If the amount is excessive, the heat resistance and mechanical properties are lowered, which is not appropriate.

In the present invention, it is desirable to add various known additives to the aromatic-aliphatic copolymerized polycarbonate together with the above-mentioned specific compound as long as the physical properties are not impaired.

Examples of the antioxidant include triphenyl phosphite, tris (4-methylphenyl) phosphite, tris (4-t-butylphenyl) phosphite, tris (monononylphenyl) phosphite and tris (2 -Methyl-4-ethylphenyl) phosphite,
Tris (2-methyl-4-t-butylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, tris (2,6-di-t-butylphenyl) phosphite, tris ( 2,4-di-t-butyl-
5-methylphenyl) phosphite, tris (monodinonylphenyl) phosphite, bis (monononylphenyl) pentaerythritol-di-phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol-di- Phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-
Phosphite, bis (2,4,6-tri-t-butylphenyl) pentaerythritol-di-phosphite, bis (2,4-di-t-butyl-5-methylphenyl) pentaerythritol-di-phosphite 2,2-methylenebis (4,6-dimethylphenyl) octyl phosphite, 2,2-methylenebis (4-t-butyl-6-
Methylphenyl) octyl phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite, 2,2-methylenebis (4,6-dimethylphenyl) hexyl phosphite, 2,2-methylenebis Phosphite compounds such as (4,6-di-t-butylphenyl) hexyl phosphite and 2,2-methylenebis (4,6-di-t-butylphenyl) stearyl phosphite, pentaerythrityl-tetrakis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5
-Di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl)
Benzene, triethylene glycol-bis [3- (3-
t-butyl-5-methyl-4-hydroxyphenyl) propionate], 3,9-bis {2- [3- (3-t-
Butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2,4.
8,10-tetraoxaspiro [5,5] undecane,
1,1,3-tris [2-methyl-4- (3,5-di-
Hindered phenol compounds such as [t-butyl-4-hydroxyphenylpropionyloxy) -5-t-butylphenyl] butane. These may be used alone or in combination of two or more.

The amount of these antioxidants to be added is
0.005 to 0.1 parts by weight, preferably 0.01 to 0.1 parts by weight, based on 100 parts by weight of the aliphatic copolymerized polycarbonate.
0.08 parts by weight, more preferably 0.01 to 0.0
If it is less than 5 weight, the desired effect cannot be obtained, and if it is excessive, the heat resistance and mechanical properties decrease, which is not appropriate.

As the ultraviolet absorber, for example, 2- (5
-Methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di-t- Butyl-2-hydroxyphenyl) benzotriazole, 2- (3-t-butyl-
5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2)
-Hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole ,
2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6-[(2H-benzotriazol-2-yl) phenol]], 2- (4,6-diphenyl-1 , 3,5-Triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2,4-dihydroxobenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-methoxy −
2'-carboxybenzophenone, dimethyl succinate-
1- (2-hydroxyethyl) -4-hydroxy-2,
2,6,6-tetramethylpiperidine polycondensate, bis (1-octyloxy-2,2,6,6-tetramethyl-
4-piperidyl) sebacate, bis (2,2,6,6-
Tetramethyl-4-piperidyl) sebacate and the like. These may be used alone or in combination of two or more.

As the release agent, those generally used may be used. For example, natural and synthetic paraffins, silicone oil, polyethylene waxes, beeswax, monoglyceride stearate, monoglyceride palmitate, pentaerythritol tetrastearate And the like, and these may be used alone or in combination of two or more.

Other flame retardants, antistatic agents, pigments, dyes and the like can be used alone or in combination as required. There are no particular restrictions on the timing of addition, the method of addition, and the form of addition, but it is preferable to add it simultaneously with or after adding the catalyst deactivator.

The timing of adding these catalyst deactivators, additives, etc. to the aromatic-aliphatic copolymerized polycarbonate is not limited. For example, a method in which the resin is added after the polycondensation reaction is completed while the resin is in a molten state, Alternatively, a method of once re-melting and mixing after cooling and pelletizing may be mentioned. Especially, after the polycondensation reaction, while the resin is in a molten state, the resin is quickly introduced into the extruder, and a catalyst deactivator, additives, etc. are added immediately after the introduction of the resin, so that the heat resistance during molding or the production of the product can be improved. It is preferable not only to improve the properties and the like, but also to suppress thermal degradation in the extrusion step. The method of addition is not particularly limited, and examples thereof include a method of directly charging and mixing into a polymerization vessel, and a method of kneading using a single-screw or twin-screw extruder. Examples of the form of addition include a method of adding the compound as it is without diluting, a method of adding the compound after dilution with a soluble solvent, and a method of adding the compound in the form of a master batch, but are not particularly limited.

After deactivation of the catalyst, a step of degassing and removing low boiling compounds in the polymer at a temperature of 200 to 280 ° C. under reduced pressure may be provided. For this purpose, paddle blades, lattice blades, eyeglass blades, etc. A horizontal stirring device having a stirring blade having excellent surface renewability, a multi-vent twin screw extruder, or a thin film evaporator is preferably used.

In the method of adding a catalyst deactivator or other additives in the present invention, when a multi-vent twin screw extruder is used, the temperature of the molten resin is preferably from 230 ° C to 2 ° C.
It is desirable to control at 80 ° C, more preferably within the range of 240 ° C to 270 ° C. When the temperature is lower than this temperature, the additive is not dispersed, and the effect is not exhibited. On the other hand, if it is higher than this, thermal deterioration is accelerated and causes coloring.

When the resin of the present invention is used for optical applications, it is desirable to manufacture the resin in an environment such as a clean room or a clean booth in order to prevent foreign substances from entering the product. In this case, it is effective to install a raw material filter, mount a cooling water filter used for pelletizing, or mount a polymer filter at the outlet of the extruder to prevent foreign matter from entering.

The transesterification according to the present invention can be carried out by a known melt polycondensation method. That is, melt polycondensation is carried out using the above-mentioned raw materials and a catalyst while removing by-products by transesterification under heating or normal pressure or reduced pressure. The reaction is generally carried out in two or more stages.

Specifically, the first-stage reaction is carried out at 120 to 2
The reaction is performed at a temperature of 50 ° C, preferably 180 to 240 ° C, for 0 to 5 hours, preferably 0.5 to 3 hours. Next, the reaction temperature is increased while increasing the degree of reduced pressure of the reaction system to carry out the reaction between the aromatic dihydroxy compound, the aliphatic dihydroxy compound and the aromatic carbonic acid diester, and finally, at a temperature of 200 to 250 ° C. under a reduced pressure of 133 Pa or less. To carry out a polycondensation reaction. Such a reaction may be a continuous type or a batch type. As the reaction apparatus used for performing the above reaction, a tank type, an extruder type, or a horizontal type stirring apparatus equipped with a stirring blade excellent in surface renewability, such as a paddle blade, a grid blade, and an eyeglass blade, is used.

[0042]

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

(1) Weight average molecular weight (Mw) GPC (Shodex GPC system 21,
Using a column temperature of 40 ° C.), the molecular weight was measured as a polystyrene equivalent molecular weight (weight average molecular weight: Mw). Chloroform was used as a developing solvent. (2) Solution hue (YI value) 9.0 g of a sample was dissolved in 90 ml of methylene chloride, and 5.
A YI value (yellow index) was measured using a 0 cm quartz glass cell. A spectrocolor meter SE-2000 manufactured by Nippon Denshoku Industries Co., Ltd. was used as a color difference meter.

Example 1 A raw material molar ratio (diphenyl carbonate / (BPZ + TCDDM)) in a first vertical stirring polymerization tank (reaction conditions: 13330 Pa, 205 ° C., stirring speed 160 rpm) under a nitrogen gas atmosphere substantially free of oxygen. ) Is 1.01 with sodium hydrogen carbonate as a catalyst in BPZ (mo
l) and a fixed ratio of diphenyl carbonate and BPZ (diphenyl carbonate / BP)
Z (molar ratio) = 2.02), and the molten mixture was continuously supplied to the first polymerization tank at a flow rate of 54.3 kg / h, and at the same time, TCDDM was supplied at a flow rate of 15.2 kg / h. It is supplied continuously, and the average residence time in the first polymerization tank is 60
The liquid level was kept constant while controlling the opening of the valve provided in the polymer discharge line at the bottom of the tank so that the liquid level could be reduced.
The polymerization liquid (prepolymer) discharged from the bottom of the tank is continuously supplied to the second, third and fourth vertical polymerization tanks and the fifth horizontal polymerization tank (Hitachi Seisakusho Co., Ltd. eyeglass wing polymerization machine (trade name)). ). The average residence time was controlled to 60 minutes for each of the second to fourth vertical polymerization tanks, and 90 minutes for the fifth horizontal polymerization tank, and the phenol by-produced was also distilled off at the same time. . The polymerization conditions of each of the second to fifth polymerization tanks are as follows: a second polymerization tank (220 ° C., 2000 Pa, stirring speed 160 rpm), a third polymerization tank (230 ° C., 40 Pa, stirring speed 60 rpm), and a fourth polymerization tank ( 240 ° C, 40P
a, stirring speed 20 rpm), fifth horizontal polymerization tank (245
° C, 40 Pa, and stirring speed 5 rpm). The polymer discharged from the fifth horizontal polymerization tank is continuously introduced in a molten state into a 3-vent type twin-screw extruder (46 mm twin-screw extruder manufactured by Kobe Steel Ltd.), and the vent port closest to the resin supply port is provided. Before the process, additives described later were supplied in the form of a master batch at a ratio of 2% by weight to the resin by a side feed compactor. After devolatilization at each vent, the mixture was cooled with water and pelletized. The composition of the master batch is Iupilon H-4000
Based on a flake-like product (trade name: polycarbonate manufactured by Mitsubishi Gas Chemical Co., Ltd.), 1 ppm of phosphorous acid (manufactured by Kanto Chemical Co., Ltd.) is added to 100 parts by weight of an aromatic-aliphatic copolymerized polycarbonate. , Dodecylbenzenesulfonic acid butyl phosphonium salt (manufactured by Takenaka Yushi Co., Ltd.) is 50 pp
m, Tris (2,4-di-t-butylphenyl) phosphite (manufactured by Asahi Denka Kogyo Co., Ltd .; trade name: ADK STAB 21)
12) is 300 ppm, 5,7-di-t-butyl-3-
(3,4-dimethylphenyl) -3H-benzofuran-
2-one (trade name: HP-136; manufactured by Ciba Specialty Chemicals Co., Ltd.) is 100 ppm, and pentaerythritol tetrastearate (produced by NOF Corporation) is 300 p.
pm, 2,2'-methylenebis [4- (1,1,3,3
-Tetramethylbutyl) -6-[(2H-benzotriazol-2-yl) phenol]] (Asahi Denka Kogyo Co., Ltd.)
(LA-31), 900 ppm, and 0.3 ppm of a toning agent (Diaresin Blue-G, manufactured by Mitsubishi Chemical Corporation). The weight average molecular weight of the obtained polycarbonate was 56,500, and the YI value was 0.95.

Comparative Example 1 A polycarbonate was produced in the same manner as in Example 1 except that the polymerization conditions in the fifth horizontal polymerization tank were 260 ° C., 80 Pa, and the stirring speed was 5 rpm. The weight average molecular weight of the obtained polycarbonate was 57200 and the YI value was 1.42.

[0046]

According to the present invention, an aromatic-aliphatic copolymer polycarbonate having an excellent hue can be stably produced, and the present invention is an industrially extremely effective method.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Sasaki 2-4-1, Hinagahigashi, Yokkaichi City, Mie Prefecture Inside the Yokkaichi Plant of Mitsubishi Gas Chemical Co., Ltd. (72) Inventor: Toshihiro Nomura 2-4-1, Hinagahigashi, Yokkaichi-shi, Mie Prefecture F-term (reference) 4J029 AA09 AB04 AC03 AD01 AE02 AE04 AE05 BD09A BD10 HC03 HC05A JA011 JA091 JA111 JA261 JB041 JB131 JB171 JB191 JC021 JC031 JC091 JC261 JC581 JC731 JF021 JF031 JF041 JF051 JF131 JF141 JF151 JF161 KC01 KD01 KD05 LA10 LA01

Claims (5)

[Claims] 1. Melt polymerization of an aromatic carbonic diester with at least one aliphatic dihydroxy compound having an alicyclic structure and at least one aromatic dihydroxy compound in the presence of an alkali metal and / or alkaline earth metal catalyst. In the preparation of the aromatic-aliphatic copolymerized polycarbonate to be produced, the operating temperature of the final polycondensation reactor is set at 250.
A method for producing an aromatic-aliphatic copolymerized polycarbonate, wherein the molecular weight of the produced polymer is controlled by setting the pressure to 133 ° C. or lower and the pressure to 133 Pa or lower. 2. The final operating temperature of the polycondensation reactor is 245.
The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 1, wherein the molecular weight of the generated aromatic-aliphatic copolymer is maintained at a predetermined value by controlling the temperature to not more than ° C. 3. The aromatic-aliphatic copolymer according to claim 1, wherein the at least one aromatic dihydroxy compound is 1,1-bis (4-hydroxyphenyl) cyclohexane. Method for producing polycarbonate. Embedded image 4. The dihydroxy compound having at least one alicyclic structure is tricyclo (5.2.1.0 ^2,6 )
5. Any one of claims 1-4, which is decandimethanol.
The method for producing an aromatic-aliphatic copolymerized polycarbonate according to the above item. Embedded image 5. The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 1, wherein the aromatic carbonic acid diester is diphenyl carbonate.