JPH0616794A - Production of polyestercarbonate - Google Patents

Abstract

PURPOSE:To obtain a polyestercarbonate excellent in hydrolysis resistance and useful for domestic appliances, glass products, etc., by subjecting a dihydric phenol and a carbonic diester to a transesterification reaction in the presence of an aromatic dicarboxylic acid ester and a specific prepolymer. CONSTITUTION:A dihydric phenol compound such as bisphenol A and a carbonic diester such as diphenyl carbonate to a transesterification reaction in the presence of an aromatic dicarboxylic ester such as diphenyl terephthalate and an aromatic polycarbonate.prepolymer containing >=30mol.% of 3,3',5,5'- tetramethylbisphenol A.carbonate units of the formula and having a mol.wt. of 1000-15000 preferably in an amount of 1-20wt.% (based on the whole amount of the polymer) are subjected to a transesterification reaction, and subsequently to a polycondensation reaction to obtain the objective polymer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a polyester carbonate by a transesterification method. More specifically, in producing a polyester carbonate from a dihydric phenol and a carbonic acid diester in the presence of an aromatic dicarboxylic acid ester by a transesterification reaction,
A prepolymer of aromatic polycarbonate or copolycarbonate containing 3,3 ', 5,5'-tetramethylbisphenol A / carbonate unit was allowed to be present to carry out a transesterification reaction, followed by a polycondensation reaction to obtain excellent hydrolysis resistance. It is a method for producing a polyester carbonate.

[0002]

2. Description of the Related Art Improving hydrolysis resistance has been mentioned as one of the problems that require improvement of polycarbonate. As an improvement measure, a method of adding an epoxy compound is disclosed in, for example, JP-A-46-5396, JP-A-49-99745 and JP-A-56.
-88456 publication. Also, alkyl / phenols were added as chain terminators during polymerization.
A method of imparting hydrolysis resistance by forming a polycarbonate having a phenol end is found in JP-A-55-45792. Further, in JP-A-47-13345 and JP-A-47-13346, hydrolysis resistance is improved by using bichloroformate of dimethyl-substituted bisphenols such as bis (dimethylhydroxyphenyl) propane. . However, these are related to the polycarbonate obtained by employing the phosgene method, which has a problem of toxicity and has a large production constraint, and is not based on the transesterification reaction as in the present invention.

[0003]

Means for Solving the Problems As a result of intensive studies on the improvement of the hydrolysis resistance, the present inventors have arrived at a method for producing a polyester carbonate having excellent hydrolysis resistance by a transesterification reaction very easily. .

That is, according to the present invention, when a polyester carbonate is produced by a transesterification reaction from a divalent phenol and a carbonic acid diester in the presence of an aromatic dicarboxylic acid ester, the following formula (I) 3, 3 ', 5,
A method for producing a polyester carbonate, characterized in that an aromatic polycarbonate prepolymer containing 30 mol% or more of 5'-tetramethylbisphenol A.carbonate units is allowed to exist to carry out a transesterification reaction, followed by a polycondensation reaction. It is provided.

[0005]

[Chemical 2]

Examples of the dihydric phenols used in the present invention include bisphenol type compounds represented by the following formula (II), which may be used alone or in a mixture.

[0007]

[Chemical 3]

A divalent group represented by -O-, -S-, -SO-, and -SO _2- is shown. R ₁ and R ₂ represent hydrogen, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group and a phenyl group, and R ₁ and R ₂ may be the same kind. Further, they may be of different types. Further, m is a positive integer of 4 to 7, and n is a positive integer of 1 to 3. ) Specific examples of the bisphenol type compound include 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl-1,2-ethane, and 4,4'-dihydroxydiphenyl-
1,1-ethane, 4,4'-dihydroxydiphenyl-1,1
-Butane, 4,4'-dihydroxydiphenyl-1,1-isobutane, 4,4'-dihydroxydiphenyl-2,2-propane, 4,4'-dihydroxydiphenyl-2,2-butane, 4, 4'-dihydroxydiphenyl-2,2-pentane, 4,4'-dihydroxydiphenyl-2,2- (4-methylpentane), 4,4'-dihydroxydiphenyl-diphenylmethane, 4,4'-dihydroxy Diphenylphenylmethylmethane, 4,4'-dihydroxydiphenyl-1,
1-cyclopentane, 4,4'-dihydroxydiphenyl-1,1-cyclohexane, 4,4'-dihydroxy diphenyl ether, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxy-diphenyl sulfide, 4 ,Four'
-Dihydroxy diphenyl sulfoxide, 4,4'-
Examples thereof include dihydroxy / diphenyl sulfone. Furthermore, these dihydric phenols are the main components, and some of them are dihydroxybenzene, dihydroxynaphthalene, dihydroxybiphenyl or aromatic compounds containing two phenolic hydroxyl groups including their substituent derivatives. It may be replaced.

The carbonic acid diester used in the present invention includes diphenyl carbonate, bis (p-chlorophenyl) carbonate, bis (o-chlorophenyl) carbonate, bis (p-nitrophenyl) carbonate and bis (o-nitro). Examples include diaryl carbonates having unsubstituted and nuclear substituents such as phenyl) carbonate and ditolyl carbonate.

The polyester carbonate referred to in the present invention is specifically an aromatic polyester carbonate, and the presence of an aromatic dicarboxylic acid ester is required when an aromatic polyester carbonate is produced by a transesterification reaction. Such aromatic dicarboxylic acid esters include terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, dimethyl ester such as p, p'-diphenyl dicarboxylic acid, and diphenyl ester. Be done. In the case of producing an aromatic polyester carbonate, a transesterification reaction is carried out by allowing these aromatic dicarboxylic acid esters to coexist with dihydric phenols and carbonic acid diesters.

The aromatic polycarbonate prepolymer used in the present invention is represented by the following formula (I): 3,3 ', 5,
It is a prepolymer of an aromatic polycarbonate or copolycarbonate containing 5 mol-% of 5'-tetramethylbisphenol A carbonate unit, preferably 50 mol% or more.

[0012]

[Chemical 4]

The prepolymer preferably has a number average molecular weight of 1,000 to 15,000 measured by gel permeation chromatography (GPC) using standard polystyrene for calibration, and more preferably 3,000 to 10,000. Thus, the amount of coexistence during the transesterification reaction is preferably 1 to 20% by weight of the total polymer. Further, this prepolymer may be allowed to coexist from the initial stage of the reaction, or may be added at any time during the transesterification reaction. still,
The transesterification reaction referred to here is the step of forming an initial condensate while producing a monovalent phenol from a divalent phenol and a carbonic acid diester, and about 95% of the theoretical amount of the monovalent phenol produced is distilled. It means the time until it comes out.

When the number average molecular weight of the prepolymer to be coexisted is lower than 1000, the toughness of the polymer finally obtained tends to be impaired, and when it is 15,000 or more, the melt viscosity of the reaction system is increased. And the initial transesterification rate becomes slow, which tends to cause a problem. Further, when the amount of the prepolymer to be coexisted is less than 1% by weight of the total polymer, the effect of improving the hydrolysis resistance, which is a feature of the present invention, becomes small. If it exceeds 20% by weight, the toughness of the finally obtained polymer tends to be impaired, which is not preferable. The number average molecular weight of the prepolymer is 1000-
When used in an amount of 15000, preferably 3000 to 10000, and a coexisting amount of 1 to 20% by weight based on the total polymer, hydrolysis resistance which is a feature of the present invention is not impaired without impairing the toughness of the resulting polymer. Can be exerted remarkably.

A known transesterification catalyst is used in the reaction. As these catalysts, simple substance of alkali metal or alkaline earth metal, its oxide, hydroxide, hydride,
Basic catalysts such as amidated compounds, carbonates, acetates, alcoholates and phenolates, quaternary ammonium hydroxide, 4-dimethylaminopyridine, quaternary ammonium halogenide, lithium aluminum hydride, quaternary ammonium Borohydride etc. are mentioned.

The transesterification reaction is carried out by using a dihydric phenol, a carbonic acid diester, a predetermined amount of 3,3 ', 5,5'-tetramethylbisphenol A.carbonate prepolymer or copolymerized prepolymer in the catalytic amount of the above transesterification catalyst. It is initiated by heating to 150 to 180 ° C. in a nitrogen atmosphere in the presence of aromatic dicarboxylic acid esters. As the reaction progresses, an aromatic or aliphatic monooxy compound is produced, so the temperature is gradually raised to 200 to 220 ° C and the pressure in the reaction system is also increased from 760 mmHg to 100 to 20 mm.
It is lowered to Hg, and the produced monooxy compound is distilled off from the reaction system. Distillation of monooxy compounds, which is close to the theoretical amount, is completed in about 2 hours. The 3,3 ', 5,5'-tetramethylbisphenol A carbonate prepolymer or copolymer prepolymer may be allowed to coexist from the initial stage of the reaction, or may be added or sequentially added at any point in the process of obtaining the initial condensate. You may add. Subsequently, the temperature of the system is raised, and at the same time, the degree of vacuum in the system is further increased to proceed with the polycondensation reaction, and finally the polycondensation reaction is completed by maintaining the pressure at 270 to 290 ° C. and the pressure at several mmHg or less, preferably at 1 mmHg or less. A molecular weight polyester carbonate can be obtained.

The ratio of the total amount of the carbonic acid diester and the aromatic dicarboxylic acid ester to the dihydric phenol in the reaction should theoretically be equimolar so that a high molecular weight polyester carbonate should be obtained. In order to prevent the balance from being lost, dihydric phenols, which are relatively susceptible to thermal decomposition, are rapidly subjected to an initial condensation reaction with carbonic acid diester to obtain an intermediate that is relatively stable against thermal decomposition and to proceed the reaction. Therefore, carbonic acid diester and aromatic dicarboxylic acid ester are used in a slight excess of the theoretical amount. Further, the carbonic acid diester and the aromatic dicarboxylic acid ester may be used in a molar ratio of 5/95 to 95/5.

The polyester carbonate thus obtained may be a known antioxidant, UV absorber, filler such as kaolin, silica, mica, talc, titanium dioxide, alumina, glass fiber or carbon fiber depending on the purpose. Reinforcing agents, dyes and pigments for coloring, ester waxes, hydrocarbon waxes, release agents such as amide wax, and various additives such as flame retardants such as octabromodiphenyl and tetrabromobisphenol polycarbonate are used. It can be used for extrusion molding or injection molding as a film or sheet. Specifically, as described in Examples, this material has excellent hydrolysis resistance, so outdoor lighting equipment,
Home appliances such as microwave oven, window glass, safety glass,
Suitable for materials such as highway fences.

[0019]

EXAMPLES Next, specific contents will be described with reference to examples. First, a method for synthesizing an aromatic polycarbonate prepolymer containing 30 mol% or more of 3,3 ', 5,5'-tetramethylbisphenol A.carbonate unit used in the present invention will be specifically described.

Synthetic Example 1 284 g (1 mol) of 3,3 ', 5,5'-tetramethylbisphenol A and diphenyl.
Charge 230 g (1.075 mol) of carbonate to a uniform molten state at 150 ° C, then use lithium hydroxide as a catalyst for 3,3 ',
10 ^-3 mol% relative to 5,5'-tetramethylbisphenol A
Was added. After stirring for 1 hour, raise the temperature to 270 ° C and continue stirring for 3 hours. Then, while distilling phenol gently, the degree of vacuum is increased to 1 mmHg or less in 2 hours.
Furthermore, the temperature was raised to 300 ° C. and stirring was carried out for 30 minutes. Thus, the number average molecular weight measured by GPC was 5800 3,
A prepolymer of 3 ', 5,5'-tetramethylbisphenol A.polycarbonate was obtained. This was named Prepolymer A and used in the following examples.

Synthesis Example 2 Bisphenol A 1 was added to a reactor equipped with a stirrer, which had been replaced with nitrogen.
14 g (0.5 mol) and 4,4'-isopropylidene-bis (2,6-
Dimethyl phenyl-phenyl carbonate) 262.5 g
(0.54 mol) was charged and heated to 150 ° C. to be in a molten state. Next, as a catalyst, 1 ml of a 0.01 mol / liter aqueous solution of lithium carbonate was added with stirring, and the mixture was further stirred for 10 minutes, then the temperature was gradually raised to 200 ° C.
The pressure was reduced to mmHg and stirring was continued for 1 hour. The temperature was further raised from 200 ° C. to 270 ° C., and the degree of vacuum was gradually raised during that time to 0.1 mmHg or less in 4 hours. During this period, about 180 ml of phenol was distilled. The number average molecular weight of the obtained polymer by GPC measurement was 10,000, and the polymer obtained by purifying in a solvent of methylene chloride-methanol and a non-solvent system was bisphenol A and 3,3 ', 5 by proton nuclear magnetic resonance spectroscopy. It was a copolycarbonate prepolymer containing 50 mol% of 5,5'-tetramethylbisphenol A. This was named Prepolymer B and used in the following examples.

Example 1 228 g of bisphenol A and 207 g of diphenyl carbonate
(Molar ratio 0.97), diphenyl terephthalate 32g (molar ratio
0.10), and 20 g of the prepolymer A obtained in Prepolymer Synthesis Example 1 (corresponding to about 7.3% by weight based on the total polymer obtained after the reaction), and a chelating agent EDTA / 2 sodium as a chelating agent to prevent coloration due to metal ions. A salt (10 ^-3 mol% with respect to bisphenol A) was charged into a reactor equipped with a stirrer having a volume of 1 liter, and after purging with nitrogen, it was melted at 150 to 160 ° C. Next, 1 ml of a 0.01 mol / liter aqueous solution of lithium carbonate was added as a catalyst (10 ^-3 to bisphenol A).
Then, the temperature was gradually raised to 220 ° C. in about 3 hours. At the same time, the pressure is reduced from 100 mmHg to 20 mmHg to about 180
ml of phenol was distilled off. Subsequently, the temperature was raised and the pressure was reduced to 270 ° C. and 0.5 mmHg in about 2 hours. The reaction was continued for another hour under these conditions to obtain polyester carbonate.

A part of the obtained polyester carbonate was crushed and an extraction with acetone was attempted with a Soxhlet extractor, but no extraction of diphenyl terephthalate was observed and diphenyl terephthalate added to the reaction system was involved in the reaction. it is conceivable that. This polyester carbonate was almost colorless and transparent, and the intrinsic viscosity [η] of the methylene chloride solution at 20 ° C. was 0.489. Further, as an evaluation of heat resistance, the thermal decomposition behavior was measured with a differential thermogravimetric analyzer (manufactured by Rigaku Denki Co., Ltd.) in a nitrogen stream at a temperature rising rate of 10 ° C./min. Decomposition start temperature (T _d ) is 413 ° C,
The temperature (T ₅ ) at which the weight loss reached 5% was 464 ℃,
The temperature at which 10% was reached (T ₁₀ ) was 477 ° C. Also, in order to evaluate the hydrolysis resistance, 50 mm × 50 mm × 0 by hot pressing.
A 6 mm thick sheet was prepared and hung in a thermo-hygrostat at 90 ° C and 100% RH, and degradation due to hydrolysis was evaluated from the decrease in intrinsic viscosity after 30 days and the appearance of the sheet. The intrinsic viscosity after 30 days is 0.464, and the retention rate for the initial intrinsic viscosity is 9
It was 4.9% and the appearance of the sheet was transparent without any cloudiness or white spots and no abnormalities were observed. These results are summarized in Table 1 together with other examples and comparative examples.

Example 2 In Example 1, instead of diphenyl terephthalate, diphenyl isophthalate was used in an amount of 64 g, and instead of Prepolymer A, bisphenol A having a number average molecular weight of 10000 obtained in Prepolymer Synthesis Example 2 was used. Same as with 40 g of 3,3 ', 5,5'-tetramethylbisphenol A (1: 1 molar ratio) copolycarbonate prepolymer B (corresponding to about 14.6% by weight based on the total polymer obtained after the reaction). Was polymerized. When the polymerization is completed, the hindered phenol “IRGANOX” from Ciba Geigy is used as an antioxidant.
0.5 g of 1010 (registered trademark) (corresponding to about 0.2% by weight based on the total polymer) was added, and stirring was continued for 30 minutes at 270 ° C. under a nitrogen atmosphere. Table 1 shows the hue, intrinsic viscosity, thermal decomposition behavior and hydrolysis test result of the obtained polyester carbonate.

Comparative Example 1 For comparison, the experiment of Example 1 was carried out without the addition of prepolymer A. After the completion of the polymerization, 0.5 g (corresponding to about 0.2% by weight based on the total polymer) of hindered phenol "Irganox 1010 (registered trademark)" manufactured by Ciba-Geigy Co. was added in order to impart oxidation resistance stability.

As seen in the comparative example, when the prepolymer containing 3,3 ', 5,5'-tetramethylbisphenol A.carbonate unit is not contained in the polymer, 90 ° C, 100% RH
After 30 days under these conditions, the intrinsic viscosity immediately after polymerization is reduced to the order of 70%, the appearance of the polymer sheet becomes cloudy, and white spots are generated at the same time. Is not observed, the decrease in intrinsic viscosity is in the 90% range, and the hydrolysis resistance is remarkably improved.

[0027]

[Table 1]

* 1 Measured at 20 ° C. in methylene chloride solution * 2 Measured at a temperature rising rate of 10 ° C./min in N ₂ gas stream T _d is the weight loss start temperature, T ₅ is the temperature at the time of weight loss 5%,
T ₁₀ indicates the temperature at the time of weight loss of 10%. * 3 Intrinsic viscosity retention indicates the ratio of the intrinsic viscosity after the hydrolysis resistance test to the intrinsic viscosity of the polymer.

Claims (2)

[Claims] 1. When a polyester carbonate is produced from a divalent phenol and a carbonic acid diester in the presence of an aromatic dicarboxylic acid ester by a transesterification reaction, 3,3 ′, represented by the following formula (I), A polyester carbonate characterized by carrying out a transesterification reaction in the presence of an aromatic polycarbonate prepolymer containing 30 mol% or more of 5,5'-tetramethylbisphenol A.carbonate unit, followed by a polycondensation reaction. Method. [Chemical 1] 2. The method for producing a polyester carbonate according to claim 1, wherein the aromatic polycarbonate prepolymer has a molecular weight of 1000 to 15000, and the amount is 1 to 20% by weight based on the total amount of the polymer.