JP2002308982A - Manufacturing method for aromatic-aliphatic copolycarbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for an aromatic-aliphatic copolycarbonate having excellent hue. SOLUTION: The aromatic-aliphatic copolycarbonate is manufactured by melt polymerizing an aromatic carbonate, at least one dihydroxy compound having an alicyclic structure and at least one aromatic dihydroxy compound in the presence of an alkali metal compound catalyst and/or an alkaline earth metal compound catalyst wherein the aromatic dihydroxy compound to be used satisfies that the mixture of the aromatic hydroxy compound and the aromatic carbonate in, the weight ratio of 1:1 shows a molten Hazen's number of not more than 50 when it is kept at 260 deg.C for 3 hours in the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a method for producing an aromatic-aliphatic copolymerized polycarbonate, and more particularly to a method for producing an aromatic-aliphatic copolymerized polycarbonate resin having excellent hue.

[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 such a drawback of the BPA-polycarbonate, a copolymerized 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 another production method, a transesterification method in which a carbonic acid diester and a dihydroxy compound are polycondensed in a molten state is known. However, in this production method, the polymerization conditions are high temperature and long time, so it is easy to color, and the catalyst remaining in the polymer causes deterioration of the polymer physical properties. Particularly, in the polycarbonate containing an aliphatic structure, the tendency is increased. It was remarkable.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a process for producing a transesterification aromatic-aliphatic copolymerized polycarbonate having a very good hue.

[0004]

Means for Solving the Problems In view of the above circumstances, the present inventors have conducted intensive studies and as a result, have found that by using an aromatic dihydroxy compound satisfying specific conditions, an aromatic compound having an extremely good hue can be obtained. The inventors have found that an aliphatic copolymerized polycarbonate can be obtained, and have completed the present invention.

[0005] That is, the present invention provides an aromatic carbonate diester and at least one dihydroxy compound having an alicyclic structure and at least one aromatic dihydroxy compound, in the presence of an alkali metal compound and / or an alkaline earth metal compound catalyst. Below, when producing an aromatic-aliphatic copolymerized polycarbonate by melt polymerization, a molten Hazen color of a mixture of an aromatic dihydroxy compound and a carbonic acid diester at a weight ratio of 1: 1 was maintained at 260 ° C. in the atmosphere for 3 hours. An object of the present invention is to provide a method for producing an aromatic-aliphatic copolymer polycarbonate having an extremely good hue by using an aromatic dihydroxy compound having a number of 50 or less.

According to the present invention, a mixture of an aromatic dihydroxy compound and a carbonic acid diester in a weight ratio of 1: 1 is used in the atmosphere.
It is characterized by using an aromatic dihydroxy compound having a molten Hazen color number of 50 or less, preferably 40 or less, more preferably 30 or less after holding at 60 ° C. for 3 hours.

As the aromatic dihydroxy compound used in the reaction of the present invention, 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- Bisphenols such as bis (4-hydroxy-3,5-dibromophenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane and 1,1-bis (4-hydroxyphenyl) cyclohexane; 4,4 ′
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. Also, two or more of these aromatic dihydroxy compounds can be used in combination.

It has an alicyclic structure used in the reaction of the present invention.
Examples of dihydroxy compounds include, for example, tricyclo
(5.2.10^2,6) Decandimethanol, β, β,
β ', β'-tetramethyl-2,4,8,10-tetrao
Kisspiro [5,5] undecane-3,9-diethanol
(Spiroglycol), pentacyclo [9.2.1.
1 ^3,9. 0^2,10. 0^4,8Pentadecane dimethanol, pe
Nantacyclo [9.2.1.1^4,7. 0^2,10. 0^3,8]pen
Tadecan dimethanol, 2,6-decalin dimethanol
Alternatively, 1,4-cyclohexanedimethanol and the like are listed.
I can do it. Among these, in particular, tricyclo (5.2.
10^2,6) Decane dimethanol (hereinafter abbreviated as TCDDM)
Is preferred. Dihydroxylation having the above alicyclic structure
The compound has a carbonyl content of KO contained as an impurity.
10 mg / g or less in H conversion, preferably 0.5 mg, more preferably
Preferably, the amount is less than 0.1 mg. Ma
In addition, the content of chlorine and metal ions is less than 1 ppm each
Are preferred.

The aromatic carbonic diester used in the reaction of the present invention includes, for example, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate, bispropylphenyl carbonate, bisoctylphenyl carbonate, bisnonylphenyl carbonate, bismethoxyphenyl carbonate, bismethoxyphenyl carbonate Substituted diphenyl carbonates such as ethoxyphenyl carbonate are exemplified, but diphenyl carbonate is particularly preferred. 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 0.97 to 1.2 mol, particularly preferably 0.99 to 1.1 mol, per mol.

In producing the aromatic-aliphatic copolymerized polycarbonate in the present invention, the aromatic carbonate diester is preferably 1.00 to 1.30 mol, preferably 1.00 to 1.30 mol, per 1 mol of the total of the aromatic dihydroxy compound and the aliphatic dihydroxy compound. Is used in an amount of 1.05 to 1.10 mol.

In the present invention, an aromatic-aliphatic copolymer polycarbonate is produced by a transesterification reaction of at least one dihydroxy compound having an alicyclic structure and at least one aromatic dihydroxy compound with a carbonic acid diester. In this case, a polymerization catalyst can be used to increase the polymerization rate.

As the polymerization catalyst, organic acid salts such as alkali metal compounds and alkaline earth metal compounds, inorganic salts, oxides, hydroxides, hydrides and alkoxides are preferably used. These compounds may be used alone or in combination. Can be used.

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.

Further, the alkaline earth metal compounds include:
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 polymerization catalysts are used in an amount of 10 ^-9 to 10 ^-3 mol, preferably 10 ^-7 to 10 ^-5 mol, per 1 mol of the total of the dihydroxy compound.

In the present invention, it is obtained as described above.
A catalyst deactivator, an antioxidant, an ultraviolet absorber, a release agent, and the like can be added to the aromatic-aliphatic copolymer polycarbonate within a range not to impair the object of the present invention.

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 and aromatic sulfonic acid compound to be added is 1/5 of the neutralization equivalent to the catalyst of the alkali metal compound and / or the alkaline earth metal compound.
The amount is up to 20 times, preferably 1/2 to 10 times. 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.

These deactivators may be used alone or in combination of two or more.

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 sulfonic acid salt to be added 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.

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, 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. The order of adding the various additives is preferably simultaneous with the catalyst deactivator or after the catalyst deactivator is added.

The timing of adding these catalyst deactivators, additives and the like to the aromatic-aliphatic copolymerized polycarbonate is not limited. 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 devolatilizing and removing low boiling compounds in the polymer at a temperature of 200 to 300 ° C. under reduced pressure may be provided. For this purpose, paddle blades, lattice blades, spectacle 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 30 ° C.
It is desirable to control the temperature at 0 ° 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.

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 the catalyst while removing by-products by transesterification under heating or normal pressure or reduced pressure. The reaction is generally carried out in two stages.

Specifically, the first-stage reaction is carried out at 120 to 2
The reaction is carried out 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 pressure reduction of the reaction system to carry out the reaction of the aromatic dihydroxy compound, the aliphatic dihydroxy compound and the aromatic carbonic acid diester. The polycondensation reaction is carried out at a temperature of 200 to 300 ° C. under reduced pressure. Such a reaction may be a continuous type or a batch type. The reaction apparatus used for performing the above reaction is a tank type,
An extruder type or a horizontal stirrer equipped with a stirrer having excellent surface renewability, such as a paddle blade, a lattice blade, and an eyeglass blade, is used.

[0032]

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) The method for measuring the weight average molecular weight (Mw) is as follows. GPC (Shodex GPC system 1
Using 1), it 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) The measurement of the solution hue (YI value) is as follows. Dissolve 9.0 g of sample in 90 ml of methylene chloride,
A YI value (yellow index) was measured using a quartz glass cell. A spectrocolor meter SE-2000 manufactured by Nippon Denshoku Industries was used as a color difference meter. (3) APHA (Hazen unit color number) measurement A powder obtained by mixing DPC and BPZ at a ratio of 1: 1 was put in a colorimetric tube, plugged, and kept in an oil bath heated to 260 ° C. for 3 hours. The APHA value was determined by comparing with the APHA standard solution at the time when was coincident with the marked line. APHA standard solution is J
Prepared based on IS K0071-1: 1998.

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 by mixing calcium acetate as a catalyst with 6 μmol based on BPZ (mol) and diphenyl carbonate and BPZ mixed at a constant ratio (diphenyl carbonate / BPZ (molar ratio) = 2.02). 54.3 of the melted mixture
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 into a 3-vented twin-screw extruder (46 mm twin-screw extruder manufactured by Kobe Steel, Ltd.) in a molten state, and immediately before the vent port closest to the resin supply port. The additives described later were supplied in a master batch form at a ratio of 2 wt% to the resin by a side feed compactor, devolatilized at each vent, and then formed into water-cooled pellets. The composition of the masterbatch is based on flakes of Iupilone H-4000 (polycarbonate manufactured by Mitsubishi Gas Chemical), and the addition amount of phosphorous acid (manufactured by Tokyo Kasei Kogyo) is 1 equivalent of the neutralization equivalent of calcium acetate.
Bis (2,6-di-t-) was added to a 0-fold amount [30 μmol / mol (based on the total moles of BPZ and TCDDM)] and 100 parts by weight of the aromatic-aliphatic copolymerized polycarbonate.
Butyl-4-methylphenyl) pentaerythritol-
Di-phosphite (PEP-36 manufactured by Asahi Denka Kogyo) is 3
00 ppm, triethylene glycol-bis [3- (3-
t-butyl-5-methyl-4-hydroxyphenyl) propionate] (IRGANOX245; manufactured by Ciba Specialty Chemicals), 200 ppm, octadecyl-3
-(3,5-di-t-butyl-4-hydroxyphenyl) propionate (AO-50 manufactured by Asahi Denka Kogyo Co., Ltd.)
200 ppm, pentaerythritol tetrastearate (manufactured by NOF Corporation), 2- [2-hydroxy-
3,5-bis (α, α'dimethylbenzyl) phenyl]
-2H-benzotriazole (TINUVIN234;
It was prepared so that the content of the toner was 500 ppm (Ciba Specialty Chemicals) and the content of the toning agent (Diaresin Blue-G, Mitsubishi Chemical) was 0.3 ppm.

Comparative Example 1 The procedure of Example 1 was repeated except that BPZ having a melting Hazen color number of 70 was used. As a result, the weight average molecular weight of the obtained polymer was 55,600, and the solution hue (YI) was 1.4 to 1.8.

[0036]

According to the present invention, when an aromatic-aliphatic copolymerized polycarbonate is produced by a transesterification method,
By using an aromatic dihydroxy compound having a Melting Hazen color number of 50 or less after maintaining a mixture of an aromatic dihydroxy compound and a carbonic acid diester at a weight ratio of 1: 1 at 260 ° C. for 3 hours, excellent hue is obtained. Aromatic
An aliphatic copolymerized polycarbonate can be produced,
This is an extremely effective method industrially.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Takashi Tsunoda, Inventor 22nd Wadai, Tsukuba, Ibaraki Research Institute for Mitsubishi Gas Chemical Company, Ltd. F term in Yokkaichi Plant of Mitsubishi Gas Chemical Co., Ltd. (reference) 4J029 AA09 BB09A BB12A BB13A BD09A BD10 BF14A BG08X BH02 DB11 DB13 HC05A JF011 JF111 KB05 KB13 KD02 KE05

Claims (4)

[Claims] 1. A melt polymerization of at least one dihydroxy compound having an alicyclic structure, at least one aromatic dihydroxy compound and an aromatic carbonic acid diester in the presence of an alkali metal compound and / or an alkaline earth metal compound catalyst. In a method for producing an aromatic-aliphatic copolymer polycarbonate, a mixture of an aromatic dihydroxy compound and a carbonic acid diester in a weight ratio of 1: 1 is maintained at 260 ° C. in the air for 3 hours, and has a molten Hazen color number of 50 or less. A method for producing an aromatic-aliphatic copolymer polycarbonate, comprising using a dihydroxy compound. 2. The method according to claim 1, wherein the at least one aromatic dihydroxy compound is 1,1-bis (4) represented by the following structural formula (I).
The process for producing an aromatic-aliphatic copolymer polycarbonate according to claim 1, wherein the compound is (hydroxyphenyl) cyclohexane. Embedded image 3. The dihydroxy compound having at least one alicyclic structure is tricyclo (5.2.1.0 ^2,6 ) decane dimethanol represented by the following structural formula (II). A method for producing the aromatic-aliphatic copolymer polycarbonate according to claim 1. Embedded image 4. The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 1, wherein the aromatic carbonic acid diester is diphenyl carbonate.