JP2002293913A - Method for manufacturing aromatic-aliphatic copolymerized polycarbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an aromatic-aliphatic copolymerized polycarbonate by an ester interchange method, showing no tendency of deteriorating mechanical properties, and holding high transparency and excellent hue in an extrusion process. SOLUTION: During the period from the introduction of a molten polymer into an extruder to its discharging via a polymer filter, the maximum temperature is <= 280 deg.C and the retention time is <=10 min.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a method for producing an aromatic-aliphatic copolymerized polycarbonate resin having excellent hue and heat stability by a transesterification method.

[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). However, the method for producing this copolymerized polycarbonate is based on bischloroformate of BPA and TC
Polycondensing DDM or TCDDM and BPA,
A method of polycondensing bischloroformate of TCDDM with BPA or BPA and TCDDM, a method of polycondensing a mixture of bischloroformate of BPA and bischloroformate of TCDDM with BPA and / or TCDDM is described. It's just that. 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, a transesterification method in which a carbonic acid diester and a dihydroxy compound are polycondensed in a molten state other than the phosgene method (chloroformate method) is known. However, in this transesterification method, because of high temperature and long time polymerization conditions, it is easy to color,
Further, the catalyst remaining in the polymer causes deterioration of the physical properties of the polymer, and the tendency was particularly remarkable in polycarbonate containing an aliphatic structure.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and does not cause a decrease in mechanical properties due to a decrease in molecular weight in an extrusion step, and maintains a high transparency and a good hue in a transesterification aromatic. -To provide a method for producing an aliphatic copolymerized polycarbonate.

[0004]

Means for Solving the Problems The present inventors have made intensive studies in view of the above circumstances, and as a result, have reached the present invention. That is, the present invention is as follows.

An aromatic carbonic acid diester, a dihydroxy compound having at least one alicyclic structure and at least one
Kind of aromatic dihydroxy compound and alkali metal and /
Or, in the presence of an alkaline earth metal catalyst, in the method for producing an aromatic-aliphatic copolymerized polycarbonate to be melt-polymerized, the obtained polymer is introduced into an extruder in a molten state and then discharged through a polymer filter. Wherein the maximum temperature is 280 ° C. or less and the average residence time is 10 minutes or less.

Hereinafter, the present invention will be described in detail. The aromatic-aliphatic copolymer polycarbonate having an alicyclic structure in the present invention has a property that it is thermally weak and easily colored as compared with generally available aromatic polycarbonates such as bisphenol A. In order to prevent this coloring, the maximum temperature of the polymer in the extrusion process from the introduction of the polymer to the extruder until the polymer is discharged through the polymer filter is 280 ° C or less, preferably 270 ° C or less,
It is more effective to maintain the temperature at 260 ° C. or lower, and if it is higher than this temperature, the molecular weight is lowered and the hue is deteriorated, which is not suitable. The average residence time in the extrusion process is 1
The time is 0 minutes or less, preferably 8 minutes or less, and more preferably 5 minutes or less. If the time is longer than this, the hue is greatly deteriorated, the molecular weight is reduced, and the mechanical properties are deteriorated.

In the present invention, it is effective to install a gear pump between the extruder and the polymer filter.
As described above, the aromatic-aliphatic copolymer polycarbonate having an alicyclic structure controls the maximum temperature at 280 ° C. or lower, so that the viscosity of the polymer is high, and the resin pressure in the polymer filter is high. Problems such as an unstable discharge amount occur. By disposing the gear pump, the discharge amount is stabilized, and these problems are solved.

[0008] The temperature of the extruder and the gear pump is from 180 ° C to 2 ° C.
It is desirable that the temperature of the polymer filter is maintained at 50 ° C, preferably 190 ° C to 220 ° C, and the temperature of the polymer filter is maintained at 240 ° C to 265 ° C, preferably 245 ° C to 260 ° C.
Usually, a polymer in a molten state is introduced into an extruder at a temperature of 240 ° C. to 260 ° C., and the polymer is heated by shearing heat generated by rotation of an extruder screw, rotation of a gear pump gear, passage of a polymer filter through a filter disk, and the like. Because the temperature rises, it is preferable that the extruder, gear pump, and polymer filter be maintained at a temperature lower than the temperature of the polymer. If the viscosity is low and the viscosity increases, the pressure of the polymer increases and the filter disk breaks or the load on the motor of the gear pump or the extruder increases, which is not appropriate.

In addition, when the temperature of the extruder, gear pump, or polymer filter is raised, particularly when the polymer remains, or when the operation is completed, the cooling is caused by the generation of so-called “burn” (insoluble foreign matter colored brownish brown). It is desirable to carry out in a nitrogen atmosphere for prevention.

[0010] The regeneration cleaning of the filter disk of the polymer filter may be the same method as that generally used for polycarbonate, and may be subjected to a passivation treatment if necessary.
Alternatively, washing with an organic compound such as phenol or diphenyl carbonate is also effective.

Examples of the catalyst deactivator include 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 neutralization equivalent 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.

[0013] Phosphonium aromatic sulfonates can also be suitably used. For example, tetrabutylphosphonium benzenesulfonate, tetrabutylphosphonium p-toluenesulfonate, tetrabutylphosphonium butylbenzenesulfonate, 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 salt of the aromatic sulfonic acid is 1 to 300 ppm, preferably 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 according to the purpose 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 (mono, dinonylphenyl) 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 is no particular limitation on the timing of addition, the method of addition, and the form of addition, but it is preferable to add the catalyst simultaneously with or after the addition of the catalyst deactivator.

The timing of adding these catalyst deactivators, additives and the like to the aromatic-aliphatic copolymerized polycarbonate is not limited. For example, a method in which the polycondensation reaction is performed while the resin is in a molten state after completion of the polycondensation reaction, Alternatively, a method of once re-melting and mixing after cooling and pelletizing may be mentioned. 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, spectacle blades, etc. A horizontal stirrer equipped with a stirring blade having excellent surface renewability, a multi-vent type twin screw extruder, or a thin film evaporator is preferably used.

When the aromatic-aliphatic copolycarbonate of the present invention is used for optical applications, it is desirable to produce it in an environment such as a clean room or a clean booth in order to prevent foreign substances from entering the product. In that case, installation of a raw material filter, mounting of a cooling water filter used during pelletization, or mounting of a polymer filter at the outlet of the extruder are effective to prevent foreign matter from entering, and have a low viscosity. A raw material filter for filtering a fluid and a filter for cooling water are suitably used at 1 μm or less, and a polymer filter for filtering a resin having high viscosity is suitably at 10 μm or less, preferably 5 μm or less.

The cooling water used at the time of pelletizing is preferably ion-exchanged water or distilled water, and is usually cooled at a temperature of 20 ° C. to 80 ° C.

The aromatic carbonic diester used in the present invention is a compound represented by the following formula (II).

[0026]

Embedded image (In the formula, Ar is a monovalent aromatic group, and Ar may be the same or different.)

The aromatic carbonic diester represented by the formula (II) is, for example, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate, bispropylphenyl carbonate, bisoctylphenyl carbonate, bisnonylphenyl carbonate, bismethoxyphenyl carbonate. And substituted diphenyl carbonates such as bisethoxyphenyl carbonate, and the like. Particularly preferred is diphenyl carbonate, and the chlorine content is preferably 1 ppm or less.
Aromatic carbonic acid diester is a total of 1
It is preferably used in an amount of from 0.97 to 1.2 mol, particularly preferably from 0.99 to 1.10 mol, per mol.

Examples of the dihydroxy compound having an alicyclic structure used in the reaction of the present invention include tricyclo (5.2.1.0 ^2,6 ) decane dimethanol, β, β,
β ′, β′-tetramethyl-2,4,8,10-tetraoxaspiro [5,5] undecane-3,9-diethanol (spiroglycol), pentacyclo [9.2.1.
^13-9 . 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. Among these, in particular, tricyclo (5.2.
1.0 ^2,6 ) decane dimethanol (hereinafter abbreviated as TCDDM) is preferred. The dihydroxy compound having an alicyclic structure has a carbonyl group content as an impurity of K
Those having an OH equivalent of 1.0 mg / g or less, preferably 0.5 mg, more preferably 0.1 mg or less are used.
Further, 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 formula (III).

[0030]

Embedded image

(In the above formula (III), X is

Embedded image Wherein R ₃ and R ₄ are a hydrogen atom or a carbon atom
An alkyl group or a phenyl group 10 may form a R ₃ and R ₄ are bonded ring. R ₁ and R ₂ is a hydrogen atom or an alkyl group or a halogen having 1 to 10 carbon atoms, R ₁
And R ₂ may be the same or different. Also, m and n
Represents the number of substituents and is an integer of 0 to 4. )

Examples of the aromatic dihydroxy compound represented by the above formula (III) 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, Bisphenols such as 2-bis (4-hydroxy-3,5-dibromophenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane and 1,1-bis (4-hydroxyphenyl) cyclohexane; '
Biphenols such as -dihydroxydibiphenyl and 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxybiphenyl; bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis ( 4-hydroxyphenyl) sulfide, bis (4-
(Hydroxyphenyl) ether, bis (4-hydroxyphenyl) ketone and the like. Among these, 1,1-bis (4-hydroxyphenyl) cyclohexane (hereinafter referred to as BPZ) is particularly preferred. Further, two or more aromatic dihydroxy compounds represented by the formula (III) may be used in combination.

In the present invention, an alkali metal compound or an alkaline earth metal compound is used as a catalyst. Such compounds include organic acid salts such as alkali metals and alkaline earth metals, inorganic salts, oxides, hydroxides,
A hydride or an alkoxide is preferably used,
These compounds can be used alone or in combination.

As such an alkali metal compound,
For example, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, 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, sodium borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, Dilithium hydrogen phosphate, disodium phenylphosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, phenol sodium salt, potassium salt, cesium salt, lithium salt, etc. It is.

As the alkaline earth metal compound,
For example, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium bicarbonate, calcium bicarbonate, strontium bicarbonate,
Examples include barium hydrogen carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, magnesium phenyl phosphate and the like.

These catalysts are used in an amount of 10 ^-9 to 10 ^-3 mol, preferably 1 to 10 mol, per mol of the 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 aromatic-aliphatic copolymer polycarbonate used in the present invention has a weight average molecular weight of 30,000-2.
It is preferably 0.00000, more preferably 50,000 to 120,000.

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 60 ° 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 vacuum of the reaction system to carry out the reaction of the aromatic dihydroxy compound, the aliphatic dihydroxy compound and the aromatic carbonic acid diester, and finally, at a temperature of 200 to 300 ° 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 lattice blade, an eyeglass blade, or the like is used.

[0041]

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 11)
And the molecular weight in terms of polystyrene (weight average molecular weight: M
w). 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 was used as a color difference meter. (3) Average residence time 0.5 g of a bluing agent was added from the opening of the C1 barrel adjacent to the feed barrel for resin introduction, and the resin discharged from the die was sampled every 10 seconds, and averaged by the impulse response method. The residence time was determined.

Example 1 A raw material molar ratio (diphenyl carbonate / (BPZ + TCDDM)) in a first vertical stirring polymerization tank (reaction conditions: 13329 Pa, 205 ° C., stirring speed 160 rpm) under a nitrogen gas atmosphere substantially free of oxygen. ) Becomes 1.01 so that sodium hydroxide is used as a catalyst in an amount of 6 μmol based on BPZ (mol), and diphenyl carbonate and BPZ
And a fixed ratio (diphenyl carbonate / BPZ (molar ratio) = 2.02).
At the same time, TCDDM was continuously supplied at a flow rate of 15.2 kg / h at a flow rate of 15.2 kg / h, and the average residence time in the first polymerization tank was 60 minutes. 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. The polymerization liquid (prepolymer) discharged from the bottom of the tank continues to the second, third,
It was sequentially and continuously supplied to a fourth vertical polymerization tank and a fifth horizontal polymerization tank (Eyeglass Wing Polymerizer (trade name) manufactured by Hitachi, Ltd.). The average residence time was 60 for each of the second to fourth vertical polymerization tanks.
The level of the liquid in the fifth horizontal polymerization tank was controlled to 90 minutes, and the by-product phenol was distilled off at the same time. The polymerization conditions in each of the second to fifth polymerization tanks are respectively the second and fifth polymerization tanks.
Polymerization tank (220 ° C, 1999 Pa, stirring speed 160 rp)
m), third polymerization tank (230 ° C., 40 Pa, stirring speed 60 r)
pm), the fourth polymerization tank (240 ° C., 40 Pa, stirring speed 20)
rpm) and a fifth horizontal polymerization tank (245 ° C., 40 Pa, 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.) shown in FIG. 1 and is closest to the resin supply port. A side feed compactor (manufactured by Kobe Steel) supplies the below-mentioned additives in the form of a master batch at a ratio of 2 wt% to the resin before the vent port, devolatilizes each vent, and then a gear pump (manufactured by Kobe Steel) ) And a water-cooled pellet through a polymer filter (manufactured by Nippon Pall; filtration accuracy: 5 μm). Table 1 shows the operating conditions of the extruder, gear pump (manufactured by Kobe Steel), and polymer filter (manufactured by Nippon Pole). At this time, the maximum resin temperature was 257 ° C., the average residence time was 4 minutes and 10 seconds, and the YI value of the obtained pellet was 1.0. In addition, the molecular weight reduction (ΔMw) of the resin discharged from the die and pelletized with respect to the resin discharged from the fifth horizontal polymerization tank was −36.
It was 0. The composition of the master batch is Iupilon S-
Based on flakes of 3000 (Mitsubishi Gas Chemical polycarbonate), the amount of butyl p-toluenesulfonate (manufactured by Tokyo Kasei Kogyo; hereinafter, pTSB) is 9 times the neutralization equivalent of sodium hydroxide [27 μmol / mol (BP
With respect to the total moles of Z and TCDDM)], and aromatic-
For 100 parts by weight of the aliphatic copolymerized polycarbonate,
Bis (2,6-di-t-butyl-4-methylphenyl)
Pentaerythritol-di-phosphite (PEP-36 manufactured by Asahi Denka Kogyo Co., Ltd.) is 400 ppm, and 5,7-di-t-butyl-3- (3,4-dimethylphenyl) -3H-benzofuran-2-one (HP -136; Ciba Specialty Chemicals) 100 ppm, octadecyl-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate (AO-50 manufactured by Asahi Denka Kogyo) is 300p
pm, 300 ppm of pentaerythritol tetrastearate (manufactured by NOF Corporation), 2,2′-methylenebis [4-
(1,1,3,3-tetramethylbutyl) -6-[(2
H-benzotriazol-2-yl) phenol]]
(LA-31 manufactured by Asahi Denka Kogyo) and 1000 ppm of a toning agent (Diaresin Blue-G manufactured by Mitsubishi Chemical).

Example 2, Comparative Examples 1 and 2 Operating conditions of extruder, gear pump, polymer filter,
A polycarbonate was produced in the same manner as in Example 1 except that the maximum resin temperature and the average residence time were changed as shown in Table 1, and physical properties were evaluated. The average residence time was determined by adjusting the amount of resin introduced into the extruder. Table 1 shows the physical property evaluation results.

[0045]

[Table 1]

[0046]

According to the present invention, it is possible to produce an aromatic-aliphatic copolycarbonate which does not suffer from a decrease in mechanical properties due to a decrease in molecular weight and maintains high transparency and good hue. Is also a very effective method.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an extrusion process used in the present invention.

[Explanation of symbols]

 Reference Signs List 1 feed barrel 2 C1 barrel 3 C2 barrel 4 C3 barrel 5 C4 barrel 6 C5 barrel 7 C6 barrel 8 C7 barrel 9 C8 barrel 10 C9 barrel 11 C10 barrel 12 Adapter 1 13 Gear pump 14 Adapter 2 15 Polymer filter 16 Die head 17-19 vent DESCRIPTION OF SYMBOLS 20 Side feed compactor 21-29 Resin thermometer 30 Resin entrance pipe 31 Master batch 32 By-product, unreacted material, low molecular weight substance, discharge pipe 33 Final polymer

Continued on the front page (72) Inventor Takashi Tsunoda 22nd Wadai, Tsukuba-shi, Ibaraki Mitsubishi Gas Chemical Company, Ltd. F term in Yokkaichi Plant Co., Ltd.

Claims (8)

[Claims] An aromatic carbonic acid diester, at least one dihydroxy compound having an alicyclic structure, and at least one
Kind of aromatic dihydroxy compound and alkali metal and /
Or, in the presence of an alkaline earth metal catalyst, in the method for producing an aromatic-aliphatic copolymerized polycarbonate to be melt-polymerized, the obtained polymer is introduced into an extruder in a molten state and then discharged through a polymer filter. Wherein the maximum temperature is 280 ° C. or less and the average residence time is 10 minutes or less. 2. The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 1, wherein a gear pump is provided between the extruder and the polymer filter. 3. The process for producing an aromatic-aliphatic copolymer polycarbonate according to claim 1, wherein the temperature of the extruder and the gear pump is maintained at 180 ° C. or higher and 250 ° C. or lower. 4. The method according to claim 1, wherein the temperature of the polymer filter is maintained at 240 ° C. or higher and 265 ° C. or lower.
The method for producing an aromatic-aliphatic copolymer polycarbonate according to any one of the above. 5. The filtration accuracy of the polymer filter is 10 μm.
The method for producing an aromatic-aliphatic copolymer polycarbonate according to any one of claims 1 to 4, wherein: 6. The method according to claim 1, wherein the at least one aromatic dihydroxy compound is 1,1-bis (4-hydroxyphenyl) cyclohexane.
The method for producing an aromatic-aliphatic copolymer polycarbonate according to the above item. 7. The dihydroxy compound having at least one alicyclic structure is tricyclo (5.2.1.0 ^2,6 ) decane dimethanol represented by the following formula (I). A method for producing the aromatic-aliphatic copolymer polycarbonate according to any one of claims 1 to 6. Embedded image 8. The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 1, wherein the aromatic carbonic acid diester is diphenyl carbonate.