JP3150456B2 - Method for producing aromatic polycarbonate copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an aromatic polycarbonate copolymer. More specifically, heat resistance, heat stability, excellent oxidation resistance, good transparency,
The present invention relates to a method for producing an aromatic polycarbonate copolymer having moldability.

[0002]

2. Description of the Related Art Bisphenol A obtained by reacting phosgene with 2,2-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as bisphenol A), which is conventionally known as a typical aromatic polycarbonate, is used. Polycarbonate is used in many fields as an engineering plastic because it has many excellent properties such as excellent transparency, heat resistance, mechanical properties, and good dimensional accuracy. In particular, in recent years, its use in information discs, optical fibers, lenses and the like has been developed by utilizing its transparency. However, the heat resistance of the polycarbonate from bisphenol A is still insufficient for some applications, and the appearance of a transparent aromatic polycarbonate having better heat resistance is desired.

On the other hand, when phosgene is reacted with 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane (hereinafter abbreviated as bisphenol AF), heat resistance is improved. It is known that an aromatic polycarbonate can be obtained (Japanese Patent Publication No. 3-12283). However, polycarbonate from bisphenol AF is inferior in heat stability to polycarbonate from bisphenol A, and its glass transition temperature does not reach 160 ° C., and its heat resistance is not sufficiently satisfactory. It is also known that when phosgene is reacted with 1,1-bis (4-hydroxyphenyl) -1-phenylethane (hereinafter abbreviated as bisphenol AP), an aromatic polycarbonate having excellent heat resistance can be obtained. JP-A-60-8317). However, polycarbonate from bisphenol AP is also inferior in heat stability to polycarbonate from bisphenol A, and there is no known method for producing a polycarbonate copolymer having excellent heat stability comprising bisphenol AF and bisphenol AP. .

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aromatic polycarbonate having excellent heat resistance, heat stability and oxidation resistance, and excellent transparency and moldability.

The present inventors have conducted intensive studies on the improvement of the thermal stability and heat resistance of polycarbonate from bisphenol AF in order to achieve the above object, and as a result, focused on copolymerizing bisphenol AF and bisphenol AP.
As a result of further study on the method for producing this copolymer, particularly excellent heat resistance, heat stability, and oxidation resistance were obtained by controlling the molar ratio of phosgene to a certain range and performing a phosgenation reaction at a certain temperature or lower. It has been found that an aromatic polycarbonate copolymer having excellent transparency and moldability can be obtained. The present invention has been completed based on this finding.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method for producing an aromatic polycarbonate copolymer by reacting phosgene with an alkaline aqueous solution of a dihydric phenol mainly composed of bisphenol AF and bisphenol AP in the presence of an organic solvent. And a phosgenation reaction at a temperature of 20 ° C. or less, wherein the amount of phosgene used is 1.15 to 1.30 in a molar ratio to the total amount of bisphenol, and a method for producing an aromatic polycarbonate copolymer.

The bisphenol AF used in the present invention is obtained by reacting hexafluoroacetone with phenol. If the amount of the impurities in bisphenol AF is too large, the transparency and thermal stability of the obtained copolymer will be reduced.Thus, it is preferable that the copolymer be recrystallized. Those having a purity of 99.98% or more reduced to 0.02% or less by lithography are preferable. Bisphenol AP is obtained by the reaction of acetophenone and phenol. Bisphenol
The AP is also preferably recrystallized because the thermal stability of the obtained copolymer is reduced if the amount of impurities is too large. In particular, the amount of impurities is preferably determined by liquid chromatography by repeating the recrystallization treatment. Those having a purity of 99.95% or more, which is reduced to 05% or less, are preferred. The use ratio of bisphenol AF and bisphenol AP, that is, the copolymerization ratio, can be in a wide range, but from the viewpoint of heat resistance and heat stability, the former is 15 to 95 mol%, and the latter is 85 to 5 mol%. preferable.

The bisphenol AF and bisphenol AP may be copolymerized with other dihydric phenols in a small amount (usually 10 mol% or less). Other dihydric phenols include, for example, bisphenol A, 4,4'-dihydroxybiphenyl, bis (4-hydroxyphenyl)
Methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) phenylethane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 1,1- Bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3-phenyl-
4-hydroxyphenyl) propane, 2,2-bis (3
-Isopropyl-4-hydroxyphenyl) propane,
2,2-bis (4-hydroxyphenyl) butane, 2,
2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-)
Hydroxyphenyl) propane, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenylsulfoxide, 4,4′-dihydroxydiphenylsulfide, 3,3′-dimethyl-4,4′-dihydroxydiphenylsulfide, 4'-dihydroxydiphenyl oxide and the like.

In the method of the present invention, a phosgenation reaction is first performed. The phosgenation reaction is carried out by adding bisphenol to an aqueous alkaline solution.
Dissolve AF and bisphenol AP, add organic solvent and add 20
℃ or less, preferably subjected to a polycondensation reaction after reacting phosgene while maintaining at 10 to 15 ℃, or separately prepared an aqueous alkali solution of bisphenol AF and an aqueous alkali solution of bisphenol AP, and added an organic solvent to each 20 ℃
Hereinafter, phosgene is reacted preferably while maintaining the temperature at 10 to 15 ° C., and the obtained respective oligomers are mixed and subjected to a polycondensation reaction. In order to react phosgene with an alkaline aqueous solution of bisphenol, gaseous phosgene may be blown or mixed with liquid phosgene. Reaction temperature is 20 ° C
When the ratio exceeds the above, the decomposition of the terminal chloroformate increases, and the thermal stability of the obtained copolymer deteriorates. The amount of phosgene used should be in the range of 1.15 to 1.30 in molar ratio to the total amount of bisphenol. If it is less than 1.15, phosgene involved in the reaction is insufficient to obtain a copolymer having a sufficient degree of polymerization. If it exceeds 1.30, a large amount of terminal chloroformate remains or this terminal chloroformate is hydrolyzed. As a result, the terminal OH content increases, and the thermal stability of the obtained copolymer deteriorates. During the reaction, the pH is preferably maintained at 10 or more, and a small amount of a reducing agent such as hydrosulfite may be added during phosgenation.

The alkali used here is preferably a strongly basic compound such as an alkali metal or alkaline earth metal hydroxide, and particularly preferably sodium hydroxide, potassium hydroxide and the like. The water used for the alkaline aqueous solution is preferably ion-exchanged water, and the alkaline aqueous solution is preferably used after being deoxygenated through nitrogen gas or the like. The concentration of the aqueous alkali solution is generally 1 to 10% by weight, preferably 3 to 7%.
% By weight. The concentration of bisphenol dissolved in the aqueous alkali solution is usually 10 to 30% by weight, preferably 15 to 20% by weight, in total, of bisphenol AF and bisphenol AP. As the organic solvent, an organic solvent inert to the reaction, for example, a halogenated hydrocarbon such as methylene chloride or chlorobenzene is preferable, and the organic solvent is also preferably used after being deoxygenated as in the case of the alkaline aqueous solution.

In the present invention, a terminal terminator can be used. As the terminal stopper, for example, a predetermined amount of a monohydric phenol such as phenol or alkylphenol, or an acid halide such as phenyl chlorocarbonate or an aromatic or aliphatic carboxylic acid chloride is used by a known method.

The subsequent polycondensation reaction is usually carried out at 25 to 35.
C., preferably at a temperature of 28-30C. The reaction time is generally 10 minutes to 5 hours, preferably 30 minutes to 2 hours. It is preferable to maintain the pH at 12 or higher during the reaction. Also, a small amount of an amine-based catalyst can be used to promote the reaction. Preferred catalysts include, for example, tertiary amines and quaternary ammonium compounds such as triethylamine, trimethylamine, triethylammonium bromide and triethylammonium hydroxide, and the amount used is usually 0.0001 to 0.01 in molar ratio to the total amount of bisphenol. Preferably 0.002-
0.005. If the degree of polymerization of the aromatic polycarbonate copolymer thus obtained is too small, the obtained molded article becomes brittle, and if it is too large, the melt fluidity deteriorates, and it becomes difficult to obtain a good molded article. Is dissolved in 100 ml of methylene chloride and the specific viscosity measured at 20 ° C. is preferably in the range of 0.160 to 0.410.

The aromatic polycarbonate copolymer obtained according to the present invention may contain various additives, if necessary, such as antioxidants, heat stabilizers, light stabilizers, lubricants, release agents, flame retardants,
Dyes and pigments, antistatic agents, weathering agents, glass fibers, carbon fibers, metal fibers, and inorganic substances such as talc may be added.
These additives can be mixed in a solution, for example, mixed by any method such as a tumbler, a super mixer, a Nauta mixer, and extruded into a pellet, or processed into a fiber, a film, or another molded product. it can. Further, it may be used by mixing with other polycarbonates or other thermoplastic resins.

In particular, the aromatic polycarbonate copolymer obtained according to the present invention has a phosphite type, a phenol type,
It is preferable that at least one organic sulfur-based antioxidant is blended. Examples of the phosphite-based antioxidant used here include triphenyl phosphite, trisnonylphenyl phosphite, tris (2,
4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl-monophenyl phosphite, dioctyl-monophenyl phosphite, diisopropyl-monophenyl phosphite, monobutyl- Diphenyl phosphite, monodecyl-diphenyl phosphite, monooctyl-diphenyl phosphite,
Bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2
-Methylenebis (4,6-di-tert-butylphenyl)
Octyl phosphite, bis (nonylphenyl) pentaerythritol-di-phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol-di-
Phosphite, a triester of phosphorous acid such as tetrakis (2,4-di-tert-butylphenyl) -4,4-diphenylenephosphonite, or an ester group having an alkyl group,
Diesters and monoesters substituted with a phenyl group, an alkylaryl group or the like, and these may be used alone or in combination of two or more. Among them, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite and tetrakis (2,4-di-tert-butylphenyl) -4,4-diphenylenephosphonite are preferred. .

The phenolic antioxidant is a hindered phenolic compound having a bulky group at the ortho position to the hydroxyl group of the phenolic compound, and is, for example, triethylene glycol-bis [3- (3-tert-butyl). −5-
Methyl-4-hydroxyphenyl) propionate],
1,6-hexanediol-bis [3- (3,5-di-
tert-butyl-4-hydroxyphenyl) propionate], pentaerythritol-tetrakis [3- (3,
5-di-tert-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, N-N'-hexamethylenebis (3,5-di-tert)
-Butyl-4-hydroxy-hydrocinnamamide),
3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester, tris (3,5
-Di-tert-butyl-4-hydroxybenzyl) isocyanurate, 3,9-bis {1,1-dimethyl-2-
[Β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} -2,4
8,10-tetraoxaspiro (5,5) undecane and the like, among which pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3-
(3,5-Di-tert-butyl-4-hydroxyphenyl) propionate is preferred.

Examples of the organic sulfur-based antioxidant include tetrakis [methylene-3- (hexylthio) propionate] methane, tetrakis [methylene-3- (decylthio) propionate] methane and tetrakis [methylene-].
3- (laurylthio) propionate] methane, tetrakis [methylene-3- (octylthio) propionate] methane, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3 , 3'-thiodipropionate,
Ditridecyl-3,3'-thiodipropionate, 2,
2-thio-diethylenebis [3- (3,5-di-tert-
Butyl-4-hydroxyphenyl) propionate],
Examples thereof include 2,2-thiobis (4-methyl-6-tert-butylphenol) and 2-mercaptobenzimidazole, and among them, tetrakis [methylene-3- (laurylthio) propionate] methane is preferable.

The amount of the antioxidant is 0.001 part by weight based on 100 parts by weight of the aromatic polycarbonate copolymer.
To 1.0 part by weight.

[0018]

The present invention will be further described with reference to the following examples. The parts and percentages in the examples are parts by weight and percentage by weight, and the evaluation was performed by the following methods.

Specific viscosity: 0.7 g of the polymer was dissolved in 100 ml of methylene chloride and measured at 20.degree.

Thermal stability: 3 g of the polymer was sealed in a test tube, degassed in vacuum, heat-treated at 330 ° C. for 4 hours, and then 200 ml.
Was dissolved in methylene chloride, and the light transmittance at 600 nm was measured using a spectrophotometer U-3400 manufactured by Hitachi, Ltd. using a quartz cell having an optical path length of 10 cm.

Heat resistance: The glass transition temperature was measured at a heating rate of 10 ° C./min using DSC-910 manufactured by DuPont.

Oxidation resistance: After heating 40 g of the polymer at 280 ° C. for 4 hours in an air atmosphere in a thermostat, methylene chloride 4
And dissolved in a quartz cell having an optical path length of 25 cm.
The light transmittance at 0 to 280 nm was measured with a spectrophotometer U-3400, and was converted into the light transmittance per 1 cm of the polymer.

[0023]

Example 1 460 parts of ion-exchanged water and 52 parts of a 48.5% aqueous sodium hydroxide solution were added to a reaction vessel equipped with a stirrer, thermometer and reflux condenser, and deoxygenated by bubbling with nitrogen gas for 30 minutes. . Add hydrosulfite 0.
Add 14 parts and add 99.98% pure bisphenol AF4
2.4 parts and 99.98% pure bisphenol AP3
6.6 parts are dissolved, 300 parts of methylene chloride are added, and 29.2 parts of phosgene (molar ratio: 1.1 to 16 ° C.) is stirred at 14 to 16 ° C.
7) was blown in over about 60 minutes. Next, 9.8 parts of a 48.5% aqueous sodium hydroxide solution and 1.9 parts of p-tert-butylphenol were added, and the mixture was emulsified by stirring. The reaction was completed. After completion of the reaction, the organic phase was separated, made acidic with hydrochloric acid, and repeatedly washed with water to remove impurities, and then methylene chloride was evaporated to obtain a copolymer. The specific viscosity of this copolymer is 0.255 and the glass transition temperature is 17
It shows high heat resistance of 0 ° C and has a light transmittance of 80 after heat treatment.
% And excellent thermal stability. Oxidation resistance is also 1 in Figure 1.
As shown by (□), it is remarkably superior to the polymer from bisphenol AP and the polymer from bisphenol A.

[0024]

Example 2 A copolymer was obtained in the same manner as in Example 1 except that the amount of bisphenol AF used was 25.4 parts and the amount of bisphenol AP used was 51.2 parts. This copolymer had a specific viscosity of 0.263, a glass transition temperature of 173 ° C., showing high heat resistance, and a light transmittance after heat treatment of 79%, showing excellent thermal stability. Fig. 1 shows oxidation resistance
As shown by 2 (○), the polymer is significantly superior to the polymer from bisphenol AP and the polymer from bisphenol A.

[0025]

Comparative Example 1 A copolymer was obtained in the same manner as in Example 1 except that the amount of phosgene used was 574.3 parts (molar ratio 1.12). The specific viscosity of this copolymer is 0.15
There were only three, and it was brittle and had no practical use.

[0026]

Comparative Example 2 A copolymer was obtained in the same manner as in Example 1 except that the amount of phosgene used was changed to 692.3 parts (molar ratio: 1.35). The specific viscosity of this copolymer is 0.24
5, and the glass transition temperature was 165 ° C., but the light transmittance after the heat treatment was as low as 71%, and the heat stability was poor.

[0027]

Comparative Example 3 A homopolymer of bisphenol AP was obtained in the same manner as in Example 1 except that the amount of bisphenol AP used was 73.1 parts without using bisphenol AF. The homopolymer had a specific viscosity of 0.301 and a glass transition temperature of 179 ° C., indicating high heat resistance. However, the light transmittance after heat treatment was as low as 69%, and the heat stability was poor. It was inferior to 1 as shown by 3 (+).

[0028]

Comparative Example 4 A homopolymer of bisphenol AF was obtained in the same manner as in Example 1 except that the amount of bisphenol AF was changed to 84.7 parts without using bisphenol AP. The homopolymer has a specific viscosity of 0.191, a glass transition temperature of 158 ° C. and low heat resistance, and a light transmittance after heat treatment of 71% and low heat stability.

[0029]

Comparative Example 5 Evaluation was made in the same manner as in Example 1 using polycarbonate [Banlite AD-5503 manufactured by Teijin Chemicals Ltd.] of bisphenol A having a specific viscosity of 0.279. The glass transition temperature was 149 ° C. The heat resistance is low and the oxidation resistance is poor as shown by 4 (◇) in FIG.

[0030]

The aromatic polycarbonate copolymer obtained by the method of the present invention is particularly excellent in heat resistance, heat stability and oxidation resistance, and has good transparency and moldability. It is extremely useful as a material for various optical devices, such as headlamp lenses, various lenses, prisms, optical waveguides, connectors, optical fibers, optical disks, and liquid crystal panels, which require optical characteristics.

[Brief description of the drawings]

FIG. 1 is a chart showing the spectral light transmittance of a polymer solution after heat treatment to show the oxidation resistance of the polymer.

[Explanation of symbols]

1 Spectral light transmittance of aromatic polycarbonate copolymer of the present invention (Example 1) 2 Spectral light transmittance of aromatic polycarbonate copolymer of the present invention (Example 2) 3 Polycarbonate from bisphenol AP (Comparative Example 3) 4) Spectral light transmittance of polycarbonate (Comparative Example 5) from bisphenol A

Claims (1)

(57) [Claims] 1. A method of preparing 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane and 1,1-bis (4-hydroxyphenyl) -1-phenylethane. In producing an aromatic polycarbonate copolymer by reacting phosgene with an alkaline aqueous solution of a main dihydric phenol in the presence of an organic solvent, the amount of phosgene used is 1.15 in a molar ratio to the total amount of bisphenol.
A process for producing an aromatic polycarbonate copolymer, wherein the phosgenation reaction is carried out at a temperature of not more than 1.30 and not more than 20C.