JPH0420523A - Production of polycarbonate - Google Patents

Abstract

PURPOSE:To obtain a polycarbonate excellent in hue, heat resistance, water resistance, weathering resistance, etc., by melt-polycondensing a 2,2-bis(4- hydroxyphenyl)propane/phenol adduct of a mixture thereof with a phenol with a carbonic diester. CONSTITUTION:A process for producing a polycarbonate by melt-polycondensing a bisphenol with a carbonic diester, wherein the bisphenol comprises a 2,2-bis(4- hydroxyphenyl)propane/phenol adduct or a mixture thereof with a phenol. Although a polycarbonate produced by the melting process in which bisphenol A is used cannot be improved in hue or properties such as heat resistance, a polycarbonate excellent in hue, heat resistance, water resistance, weathering resistance, etc., can be obtained by using the above adduct or its mixture with a phenol as the above bisphenol.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polycarbonate. More specifically, the present invention relates to a method for producing polycarbonate that is tax-free and has excellent heat resistance, water resistance, weather resistance, and the like.

Animitate Niragono 11 Polycarbonate is widely used because it has excellent mechanical properties such as impact resistance, heat resistance, and transparency. Such polycarbonates can be produced by directly reacting phosgene with an aromatic organic trihydroxy compound such as suphenol (interfacial method), or by reacting an aromatic organic trihydroxy compound such as bisphenol with a carbonic acid diester such as diphenyl carbonate. A method is known in which a transesterification reaction (polycondensation reaction) is carried out in a molten state.

One such manufacturing method is to explain the method of manufacturing polycarbonate by transesterification reaction between an aromatic organic trihydroxyl compound and a carbonic diester.This method uses a metal organic acid salt, inorganic acid salt, or oxide as a catalyst ,
This is a method of transesterifying an aromatic organic trihydroxyl group compound and a carbonic acid diester under reduced pressure using a hydroxide, hydride, alcoholade, etc., while finally heating and melting at 250 to 330°C. .

This method has the advantage of producing polycarbonate at a lower cost than the blush method described above, but on the other hand,
Because the aromatic organic trihydroxy compound and the carbonic acid diester are reacted in a molten state, the resulting polycarbonate is exposed to high temperatures for a long period of time, resulting in the problem that the resulting polycarbonate tends to turn yellow. are doing.

As a method for reducing such coloring of polycarbonate, for example, a method using a highly purified aromatic organic trihydric compound can be used. Methods for industrially purifying aromatic organic trihydroxy compounds, such as 2,2-bis(4-hydroxyphenyl)propane (hereinafter sometimes referred to as "bisphenol A"), include distillation,
A recrystallization method or an adduct method is known. This 1 Adduct Method 1 This is a purification method that takes advantage of the property that bisphenol A forms a 1:1 adduct with phenol. That is, 2.2-bis(
When a large excess of phenol is added to a mixture containing impurities such as 4-hydroxyphenyl)propane (i.e., bisphenol A) and 2-(4-hydroxyphenol)-2-(2-hydroxyphenol)propane, bisphenol A Impurities do not form adducts with phenol. Therefore, after separating the precipitate, which is an adduct of bisphenol A and phenol, from the solution, the separated precipitate is heated to a temperature at which the phenol constituting the adduct evaporates (for example, 180 ℃
By blowing a moderate amount of inert gas over a long period of time), the phenol constituting the adduct is removed and bisphenol A with high purity can be obtained. The bisphenol A obtained in this way has extremely high purity and contains almost no phenol, as well as 2-(4-hydroxyphenol)-2-(2- -Hydroxyphenol)propane is also hardly contained.

Therefore, by preparing polycarbonate by a melting method using such highly purified bisphenol A, it should be possible to produce polycarbonate with excellent properties such as hue and heat resistance.

However, according to the studies of the present inventors, even if polycarbonate is produced by a melting method using bisphenol A obtained as described above, the properties such as hue and heat resistance of the resulting polycarbonate are not as good as expected. Its characteristics do not improve until In other words, when manufacturing polycarbonate, it was found that the properties of polycarbonate obtained only by using high-purity bisphenol A are not necessarily satisfactory.
The present invention is an attempt to solve the problems associated with the prior art as described above, and is to obtain a polycarbonate having excellent properties such as heat resistance, water resistance and weather resistance by a melt polycondensation method. The purpose is to provide a method for
Ru.

Summary of the Invention The first method for producing polycarbonate according to the present invention is a method for producing polycarbonate by melt polycondensation of bisphenols and diester carbonate, in which 2,2-bis(4-hydroxyphenyl) is used as the bisphenol. It is characterized by using an adduct of propane and phenols or a mixture of the adduct and phenols.

The second method for producing polycarbonate according to the present invention includes:
In the method of producing polycarbonate by melt polycondensation of bisphenols and carbonic diester, the bisphenols include an adduct of 2,2-bis(4-hydroxyphenyl)propane and phenols, or an adduct of the adduct and phenols. The content ratio of the acidic substance contained in the adduct or the mixture ζ p
- It is characterized by using an adduct or mixture treated with an alkali so that the concentration is 0.5 ppm or less in terms of sulfonic acid.

In the method for producing polycarbonate according to the present invention, as the 14-bisphenol, an addition of 2,2-bis(4-hydroxyphenyl)propane and a phenol, or a mixture obtained by further adding a phenol to this adduct is used. Therefore, it is possible to produce polycarbonate with excellent heat resistance, water resistance, weather resistance, etc.

111 Hereinafter, the method for producing polycarbonate according to the present invention will be specifically explained.

In the method for producing polycarbonate of the present invention, polycarbonate is produced by melt polycondensation of bisphenol A and diester carbonate.

In the present invention, as bisphenol A,
Use an adduct of bisphenol A and phenols, or a mixture of this adduct with additional phenols. As mentioned above, as a method for industrially refining bisphenol A, for example, a large excess of phenol is added to a condensation-dehydration reaction mixture obtained by reacting acetone and phenol in the presence of an acidic catalyst to purify bisphenol A. Selectively generate adducts with phenols, precipitate bisphenol A as an adduct with phenols, separate the precipitate from the reaction mixture, and then blow heated inert gas to separate the adducts. A method is used to purify bisphenol A by removing the phenols that constitute it. However, bisphenol A purified in this way contains trace amounts of colored impurities generated by high-temperature treatment when removing phenol, so even if it is used as is, the color tone or heat resistance of the resulting polycarbonate may be affected. In the method for producing polycarbonate of the present invention, it was found that the properties such as Use the adduct itself with class.

That is, when producing polycarbonate by the melting method, the present inventors did not remove the phenols from the adduct of 2,2-bis(4-hydroxyphenyl)propane and phenols, but carbonated the adduct as it is. It has been found that a polycarbonate with excellent hue and heat resistance can be obtained by polycondensation with a diester.Hereinafter, the method for producing polycarbonate of the present invention will be described in detail.

Bisphenol A and diester carbonate are used as raw materials for producing polycarbonate. and,
In the present invention, as this bisphenol A, 2.
Instead of using 2-bis(4-hydroxyphenyl)propane as it is, adducts of this 2°2-bis(4-hydroxyphenyl)propane and phenols are used. This 2,2-bis(4-hydroxyphenyl)
Adduct IL of propane and phenols 2.2-bis(4-hydroxyphenyl)propane and phenol are combined in a molar ratio of 1=1. can also be used in excess.

That is, in the present invention, the substituted 2.2-bis(4-hydroxyphenyl)propane and the phenol, for example,
:1 to 1:50, preferably 1:1 to 1:25, allowing the excess phenol to act like a solvent. Incidentally, even if the phenol is used in excess within the above range, the adduct can be obtained as a solid.

Such adducts are produced by adding an excess of phenols to a reaction mixture obtained by dehydrating and condensing acetone and phenol in the presence of a cation exchange resin or an acidic catalyst such as a mineral acid. It can be obtained by heating to a temperature of 0.degree. C. to prepare a homogeneous solution and then cooling it, usually from 30 to 70.degree. C., to precipitate it from the solution. The solid thus precipitated can be separated by filtration and used as it is, but it can also be used after being washed with phenol. In addition, after the adduct formed as described above is blown with a high temperature inert gas to remove the phenols constituting the adduct to obtain purified bisphenol A, this bisphenol A is Furthermore, in addition to excess phenols, adducts can also be formed. By repeating the process of forming an adduct in this manner, an adduct of bisphenol A and phenols with higher purity can be prepared.

The phenols used to form the adduct used as a raw material in the present invention include 2,2-bis(
Any phenol that can form an adduct with 4-hydroxyphenyl)propane can be used without particular limitation.
Since 4-hydroxyphenyl)propane is produced from phenol and acetone, it is preferable to use phenol.

In the present invention, by using an adduct of 2,2-bis(4=hydroxyphenyl)propane and phenols as described above as bisphenol A, a polycarbonate having a good hue and excellent heat resistance is produced. According to the second invention of the present application, such an adduct is treated with an alkali to remove generated salts, complexes, etc., and then used in a polycondensation dehydration reaction with a carbonic acid diester. This further improves properties such as color and heat resistance of the resulting polycarbonate. It is preferable to remove impurities such as neutralized salts and complexes generated in the alkali treatment as much as possible before polymerization. This is easily achieved by using the anion exchange resin described below.

That is, the present inventor conducted a detailed study on the factors that affect the properties of polycarbonate, and found that the adduct prepared as described above may contain an acidic substance, albeit in a very small amount. The substance acts as a decomposition catalyst for bisphenol A when phenol is eliminated from the adduct, and the alkali catalyst necessary for polymerization is used to deactivate the alkali catalyst used in the reaction between the adduct and carbonic acid diester. It was discovered that when used in large quantities, it may cause a decrease in color and heat resistance of the resulting polycarbonate.Although the origin of this acidic substance is not necessarily clear, the inventors have found that 2. It is believed that this is caused by the catalysts used when synthesizing 2-bis(4-hydroxyphenyl)propane, such as mineral acids and cationic ion exchange resins. In the present invention, acidic substances and compounds having a 14pKa value of substantially 4 or less are referred to as acidic substances.

In the present invention, an adduct of 2,2-bis(4-hydroxyphenyl)propane and phenols is treated with an alkali.

Here, as the alkaline treatment agent used for treating the above adduct, for example, a basic compound such as an alkali metal hydroxide such as sodium hydroxide, potassium hydroxide, calcium hydroxide or an alkaline earth metal hydroxide is used. Preference is given to using basic compounds having a nitrogen atom. As such a basic compound having a nitrogen atom, an organic basic compound such as pyridine or trimethylamine may be used. This is preferred because neutralized salts, complexes, etc. can be automatically removed. Among the anionic ion exchange resins having a nitrogen atom, the first
Gel type ion exchange resins and MR type ion exchange resins having secondary, secondary or tertiary amine groups, or quaternary ammonium groups are particularly preferably used. Examples of commercially available anion-based ion exchange resins include Amberlyte TI+1 Amberlyst fM (manufactured by Rohm and Haas), Diaion TM (manufactured by San-Nichi Kasei), and Downix Ste M (manufactured by Dow Chemical Japan Co., Ltd.). ) etc. are available.

The treatment of the adduct using such an anionic ion exchange resin is performed to reduce the content of acidic substances in the adduct (or the mixture of the adduct and phenols).
It is carried out so that the toluenesulfonic acid equivalent value is 0.5 ppm or less. Furthermore, this content is 0,3
By treating the amount to be less than 0 ppm, preferably less than O, 1 ppm, a polycarbonate particularly excellent in properties such as tax immunity and heat resistance can be obtained. It should be noted that the lower the content of acidic substances in the adduct, the better; therefore, there is no particular limit to the lower limit of this content.8 When the workability and the effect associated with the removal of acidic substances are compared, it is generally 0. It is about 0.01 ppm.

There are no particular restrictions on the method of bringing the content of the acidic substance in the adduct to the above value, and a method of bringing the adduct into contact with the anionic ion exchange resin or the like is usually employed. The contact conditions between the two may be such that the content of the acidic substance is reduced as described above.For example, the contact temperature is within the range of room temperature to 150°C, preferably 60 to 110°C; The contact time under temperature conditions is usually 1 second to 10 hours.

By reducing the content of acidic substances in the adduct to a predetermined concentration in this way, the reaction rate between the adduct and carbonic acid diester increases, thereby shortening the polymerization time until the polycarbonate reaches the desired molecular weight. I can do it. In addition, the salt concentration and catalyst concentration in the system can be reduced, and as a result, deterioration of raw materials or polycarbonate due to heating can be effectively prevented, making it possible to obtain polycarbonate with excellent properties such as heat resistance and water resistance. I can do it.

In the basic invention, the carbonic acid diester to be reacted with the adduct is specifically 14 diphenyl carbonate, ditrilyl carbonate, bis(chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(diphenyl). ) carbonate, diethyl carbonate, dimethyl carbonate, dicyclohexyl carbonate, etc. are used. These carbonic acid diesters can be used alone or in combination.

Among these carbonic acid diesters, diphenyl carbonate is particularly preferred.

Further, the carbonic acid diester used in the present invention may be a dicarboxylic acid or a mixture containing a dicarboxylic acid ester. In this way, polyester polycarbonate can be obtained by using dicarboxylic acid or dicarboxylic acid ester together with diester carbonate.
The method for producing polycarbonate of the present invention also includes this method for producing polyester polycarbonate.

In the present invention, examples of the dicarboxylic acid or dicarboxylic acid ester that can be used in combination with the carbonic acid diester include terephthalic acid, isophthalic acid, diphenyl terephthalate, and diphenyl isophthalate.

Catalyst In the present invention, when producing a polycarbonate by melt polycondensation of an adduct of 12.2-bis(4-hydroxyphenyl)propane and phenols and a carbonic acid diester, a conventionally known catalyst or the inventor of the present invention may be used. A newly developed catalyst can be used.

As such a catalyst, even if
94 or Japanese Patent Publication No. 36-13942 Specifically: Alkali metals such as lithium, sodium and potassium 1 Alkaline earth metals such as magnesium, calcium and barium; Mention may be made of acetates, carbonates, borates, oxides, hydroxides, hydrides or alcolades of metals such as cadmium, tin, antimony, lead, manganese, cobalt and nickel. Further, a catalyst in which a nitrogen-containing basic compound is combined with boric acid or a boric acid ester, a phosphorus compound, etc. can be used.

In the present invention, when manufacturing a polycarbonate by melt polycondensing the adduct of bisphenols and phenols as described above and carbonic acid diester, in particular (a),
It is preferable to use certain compounds represented by (b) and (c) in combination. (a) Nitrogen-containing basic compound (b) Alkali metal compound or alkaline earth metal compound (C) Boric acid or boric acid ester In the present invention, IL(a) is a preferred catalyst.
and (b), a catalyst that combines (a) and (C), a catalyst that combines (b) and (C), or a catalyst that combines (a), (b) and (C). Examples include catalysts.

Here, as a specific example of the nitrogen-containing basic compound (a), tetramethylammonium hydroxide (Me, NO
H), tetraethylammonium hydroxide (E7, N0
H), tetrabutylammonium hydroxide (Bu,
N OH), and trimethylbenzylammonium hydroxide (P h
Tetraalkyl, aryl, aralyl-ammonium hydroxides such as -CH2(Me), NoH) and tertiary amines such as trimethylamine, triethylamine, dimethylbenzylamine and triphenylamine (wherein R is a methyl group and Alkyl groups such as ethyl groups, secondary amines represented by aryl groups such as phenyl groups and tolyl groups), primary amines represented by RNH2 (in the formula, R is the same as above), or ammonia, tetramethylammonium Borohydride (Me4N
BH4), tetrabutylammonium borohydride (Bu, N
BH,), tetrabutylammonium tetraphenylbore)
(Bu4NBPh, ), and tetramethylammonium tetraphenylborate (
Basic salts such as Me, NBPh4) can be mentioned.

Among these, tetraalkylammonium hydroxides are particularly preferred.

Specific examples of the alkali metal compound (b) include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, Potassium acetate, lithium acetate, sodium stearate, potassium stearate, lithium stearate, sodium borohydride, lithium borohydride and sodium boroborohydride, salts formed from bisphenol A and lithium, sodium or potassium, etc. Compounds), sodium benzoate, potassium benzoate, lithium benzoate, disodium phosphate, dipotassium phosphate and dilithium phosphate may be mentioned.

Further, specific examples of the alkaline earth metal compound (b) include 1) calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, Calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate,
Mention may be made of barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate and strontium stearate.

Furthermore, specific examples of boric acid or boric acid esters (C) include boric acid or general formula %) (wherein, R represents an alkyl group such as methyl or ethyl, or an aryl group such as phenyl). , n is 1.2 or 3).

Specific examples of such borate esters include trimethyl borate, triethyl borate, tributyl borate,
Mention may be made of trihexyl borate, triheptyl borate, triphenyl borate, tritolyl borate and trinaphthyl borate.

In the present invention, when producing polycarbonate by melt polycondensation, the diester carbonate is usually 1 mole of the adduct of 2,2-bis(4-hydroxyphenyl)propane and phenols. .01-1.30 mol, preferably 1
．． It is used in an amount of 0.02 to 1.20 mol.

Note that the adduct of 2.2-bis(4-hydroxyphenyl)propane and phenols is 2.2-bis(4-hydroxyphenyl)propane and phenol.
It means an adduct in which bis(4-hydroxyphenyl)propane and phenol are bonded in a molar ratio of 1:1. Therefore, when an adduct is formed by using an excess of phenols, the amount of carbonic acid diester to be used is calculated by excluding the excess phenols.

In the reaction of the present invention, the catalysts as described above are preferably used in the amounts described below.

When using the nitrogen-containing basic compound (a), the nitrogen-containing basic compound (a) is usually used in an amount per mole of the adduct of 2,2-bis(4-hydroxyphenyl)propane and phenol. is 10-6 to 10-1 mol, preferably 10
It is used in an amount of -5 to 10-2 mol.

When using an alkali metal compound or alkaline earth compound (b), the alkali metal or alkaline earth compound (b) is 2,2-bis(4-hydroxyphenyl)
Usually 10-6 to 10-5 mol, preferably 10-7 to 1 mol of the adduct of propane and phenols.
It is used in amounts of ~10-4 mol, particularly preferably 10-7 to 10-5 mol.

Furthermore, when boric acid or boric acid ester (C) is used, boric acid or boric acid ester (C) has 2.2
-Usually 10-6 to 10
-1 mol, preferably from 10-7 to 10-2 mol, particularly preferably from 10-6 to 10-4 mol.

2. The melt polycondensation reaction between an adduct consisting of 2-bis(4-hydroxyphenyl)propane and a phenol and a carbonic diester is performed under the conventional melt polycondensation reaction conditions between a bisphenol and a carbonic diester. It can be carried out under similar conditions. Particularly in the present invention, it is preferable to react both in multiple stages, and it is particularly preferable to react both under normal pressure and then under reduced pressure.

Specifically, the first stage reaction is carried out at normal pressure and at a reaction temperature of usually 80 to 250°C, preferably 100 to 23°C.
2,2-bis(4-
The adduct formed from hydroxyphenyl)propane and phenols is reacted with a carbonic acid diester. Next, the reaction temperature is raised while reducing the pressure in the reaction system to carry out both reactions, and finally 24
The polycondensation reaction is carried out at a temperature of 0 to 320°C.

2,2-bis(4-hydroxyphenyl) as above
The reaction between the adduct formed from propane and phenols and the carbonic acid diester may be carried out continuously or batchwise. Further, there is no particular restriction on the reaction apparatus used in carrying out the above reaction, and various forms of reaction apparatuses such as a tank gourd type or a base type can be used.

By carrying out the reaction as described above, an adduct of 2,2-bis(4-hydroxyphenyl)propane and phenols used as raw materials is obtained.By heating during melt polycondensation with carbonic acid diester, 2.2-bis(4-
It is thought that polycarbonate is formed by melt polycondensation of (hydroxyphenyl)propane and phenols with carbonic acid diester either separately or as they are. Further, the adduct or polycarbonate oligomer has higher heat resistance than 2,2-bis(4-hydroxyphenyl)propane. Therefore, by using an adduct, it is possible to increase the number of heating histories of 2.2-bis(4-hydroxyphenyl)propane or the number of high temperatures required for the reaction of 2.2-bis(4-hydroxyphenyl)propane and diester carbonate. Since the exposure time is shortened, thermal decomposition of 2,2-bis(4-hydroxyphenyl)propane is effectively prevented.

Therefore, as in the present invention, by using the adduct of 2,2-bis(4-hydroxyphenyl)propane and phenols as is in the melt polycondensation reaction with carbonic diester, 2,2-bis(4-hydroxyphenyl) 4-hydroxy phenyl)
Compared to the case of melt polycondensation reaction of propane and diester carbonate, polycarbonate with excellent hue, heat resistance, etc. can be obtained.

Furthermore, by treating the adduct with alkali to reduce the content of acidic substances contained in the adduct to a specific value or less,
Since the polymerization rate can be increased and the amount of catalyst used and the amount of impurities such as salts can be reduced, thermal deterioration of raw materials or polycarbonate due to heating can be effectively prevented.

In the present invention, when producing polycarbonate by melt polycondensation of bisphenols and diester carbonate, an adduct of 2,2-bis(4-hydroxyphenyl)propane and phenols is used as bisphenols. By using this method, it is possible to obtain polycarbonate with improved heat resistance, water resistance, and weather resistance.

Furthermore, by reducing the content of acidic substances in the adduct to a predetermined value through alkali treatment, the properties of polycarbonate such as tax-free heat resistance, water resistance, and weather resistance can be improved.

[Examples] The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

In addition, the physical properties of the polycarbonate obtained in the following examples are measured as follows: intrinsic viscosity (IV)
: Hue (b value) measured using an Ubbelohde viscometer at 20°C in methylene chloride = X value, Y value Z of a press sheet with a thickness of 3-1
Co1or and Co1 manufactured by Nippon Denshoku Kogyo Co., Ltd.
orDifference Meter ND-100
The YI value measured using 1DP, and the yellowness scale is YI (yellow index), is: YI = (1,277X - 1,06
02).

Heat aging test: A 3rd thick press sheet was aged for 1000 hours in a gear oven (GHPS-21λ manufactured by Tabai Seisakusho ■, air exchange rate 71.6 times/hour) at 140°C.
Hot water test to measure hue: A three-thick press sheet was immersed in distilled water in an autoclave and held at 120°C for 5 days, then Haze
Crude bisphenol A was prepared from acetone and phenol using a cation exchange resin method.The crude hisphenol A and phenol were mixed at a ratio of 1:5 (weight ratio), and the mixture was heated to 80°C. After making a homogeneous solution, it was cooled to 42°C and the precipitated solid was filtered under a nitrogen atmosphere.Then, the filtered solid was washed with molten phenol to obtain an adduct of bisphenol A and phenol as a white solid (1 times adduct).

This additional truce is that bisphenol A and phenol are 1:
Although it is an adduct bonded at a molar ratio of 1, it has the form of a mixture containing 0.58 mole of phenol in excess of 1 mole of bisphenol A, and the molar ratio of bisphenol A and phenol in this mixture is The ratio is 1
:1.58, this adduct (mixture) obtained in this way and diphenyl carbonate (molar ratio, diphenyl carbonate/bisphenol A adduct = 1/1)
．． 12) into a glass reactor, and then tetramethylammonium hydroxide, boric acid, and sodium hydroxide were mixed in a molar ratio of 1:0.01:O, OO4, and the resulting catalyst was mixed with bisphenol. It was added in an amount of 2.5xlO<mol per mole of A, and heated at 180°C for 30 minutes in a nitrogen atmosphere to perform a transesterification reaction.Then, the resulting reaction mixture was heated to 210°C and gradually The pressure was reduced to 200 In Hg and reacted for 1 hour, then the temperature was raised to 240°C and 200 W
React with Hg for 20 minutes, and then incubate at that temperature for 150 minutes.
Gradually reduce the pressure to +uHg and react for 20 minutes, then reduce the pressure to 100wHg and react for 20 minutes, then 1
Reduce the pressure to 5 (to) IHg and react for 0.5 hours,
The temperature was raised to 70°C, the pressure was finally reduced to 0.5-IHg, and the reaction was carried out for 2.5 hours to obtain polycarbonate.

Table 1 shows the IV, hue, heat resistance, and hot water resistance of the obtained polycarbonate.

Purified bisphenol A was obtained by blowing nitrogen gas at 180°C onto the adduct of bisphenol A and phenol prepared in Example 1 to remove the phenol forming the adduct.
To obtain this purified bisphenol A, melt the purified bisphenol A, then add 5 times the amount of phenol again, cool it to 42°C, filter the precipitated solid, wash the filtered solid with molten phenol, An adduct of bisphenol A and phenol was obtained as a white solid (double adduct).

This adduct contains bisphenol A and phenol in 1:
Although it is an adduct bonded at a molar ratio of 1, it has the form of a mixture containing 0.52 mol of phenol in excess of 1 mol of bisphenol A, and the molar ratio of bisphenol A and phenol in this mixture is The ratio is 1
:1.52 Melt polycondensation was carried out in the same manner as in Example 1 except that the adduct (double adduct, mixture) obtained as described above was used to obtain a polycarbonate.

Table 1 shows the IV, hue, heat resistance, and hot water resistance of the obtained polycarbonate.

Comparative Example 1 Purified bisphenol A was obtained by blowing nitrogen gas at 180°C onto the adduct of bisphenol A and phenol obtained in Example 1 to remove the phenol constituting the adduct. Contains virtually no phenol.

In Example 1, melt polycondensation was performed in the same manner as in Example 1 except that purified bisphenol A obtained as described above was used to obtain polycarbonate.The IV, heat resistance, and hot water resistance of the obtained polycarbonate are shown below. Shown in 1.

Comparative Example 2 Purified bisphenol A was obtained by blowing nitrogen gas at 180°C onto the adduct (double adduct) of bisphenol A and phenol obtained in Example 2 to remove the phenol constituting the adduct. This purified bisphenol A is substantially free of phenol.

In Example 2, melt polycondensation was carried out in the same manner as in Example 2, except that purified bisphenol A obtained as described above was used to obtain polycarbonate. It is shown in Table 1.

In Example 1, crude bisphenol A was prepared in the same manner as in Example 1, except that hydrochloric acid was used as a catalyst when preparing crude bisphenol A from acetone and phenol. An adduct of bisphenol A and phenol was obtained in the same manner as in Example 1 (one-time adduct).

This adduct contains bisphenol A and phenol in 1:
Although it is an adduct bonded at a molar ratio of 1, it has the form of a mixture containing 0.56 mol of phenol in excess of 1 mol of bisphenol A, and the amount of bisphenol A and phenol in this mixture is The molar ratio is 1
:1.56, melt polycondensation was carried out in the same manner as in Example 1 except that purified bisphenol A obtained as above was used to obtain polycarbonate. Table 2 shows the heat resistance and hot water resistance.

Example 4 Using the adduct of bisphenol A and phenol prepared in Example 3, an adduct (double adduct) of bisphenol A and phenol was obtained in the same manner as in Example 2.t4 This adduct was Bisphenol A and phenol are 1:
It is an adduct in which the molar ratio of bisphenol A and phenol in this mixture is 0.53 mol in excess of 1 mol of bisphenol A. The ratio is 1
:1.53, melt polycondensation was carried out in the same manner as in Example 1 except that purified bisphenol A obtained as above was used to obtain polycarbonate. IV, hue, Table 2 shows the heat resistance and hot water resistance.

Comparative Example 3 Purified bisphenol A was obtained by blowing nitrogen gas at 180°C onto the adduct of bisphenol A and phenol obtained in Example 3 to remove the phenol constituting the adduct. Contains virtually no phenol.

In Example 3, melt polycondensation was carried out in the same manner as in Example 3 except that purified bisphenol A obtained as described above was used to obtain polycarbonate. It is shown in Table 2.

Comparative Example 4 Purified bisphenol A was obtained by blowing nitrogen gas at 180°C onto the adduct of bisphenol A and phenol obtained in Example 4 to remove the phenol constituting the adduct. Contains virtually no phenol.

In Example 4, melt polycondensation was performed in the same manner as above except that purified bisphenol A obtained as above was used to obtain polycarbonate.The IV, heat resistance, and hot water resistance of the obtained polycarbonate are shown below. Shown in 2.

Examples 5 to 10 In Example 2, polycarbonate was prepared in the same manner as in Example 2, except that the type and amount of the catalyst used in Example 2 were changed as shown in Table 3.

Table 3 shows the IV, hue, heat resistance, and hot water resistance of the obtained polycarbonate.

Comparative Examples 5 to 6 Polycarbonate was prepared by performing melt polycondensation according to the method of Comparative Example 1, except that the type and amount of catalyst were changed. IV, hue, heat resistance, Table 3 shows the hot water resistance.

Example 11 Crude bisphenol A was prepared from acetone and phenol using a cation exchange resin method. The crude bisphenol A and phenol were mixed at a ratio of 1:5 (weight ratio), and the mixture was heated to 80°C to form a homogeneous solution. After that, it was cooled to 42'C, and the precipitated solid was filtered under a nitrogen atmosphere.Then, the filtered solid was washed with molten phenol to obtain an adduct of bisphenol A and phenol as a white solid (one time). adduct).

In this adduct, bisphenol A and phenol are 1=
Although it is an adduct bonded at a molar ratio of 1, it has the form of a mixture containing 0.58 mole of phenol in excess of 1 mole of bisphenol A, and the molar ratio of bisphenol A and phenol in this mixture is The ratio is 1
The total amount of acidic substances (acidic substances with a pKa value of 4.0 or less) in this adduct (mixture) was 1.0 ppm in terms of p-sulfonic acid. The obtained adduct (mixture) was heated to 102°C to form an anionic ion exchange resin having a nitrogen atom (
The alkali treatment was carried out using Amberlyst TMR-21 (manufactured by Rohm and Haas) with an average residence time of 10 minutes. The total amount of the alkali-treated adduct (mixture) and diphenyl carbonate (molar ratio of diphenyl carbonate/bisphenol A addition) was 0.1 ppm or less in terms of p-sulfonic acid. Body=171.
12) into a glass reactor, and the catalyst obtained by mixing tetramethylammonium hydroxide, boric acid, and sodium hydroxide at a molar ratio of 1:0.01 + O, OO4 was added to 1 mole of bisphenol A. and heated at 180°C for 30 minutes in a nitrogen atmosphere to perform a transesterification reaction.Then, the heating operation and depressurization operation were performed in the same manner as in Example 1. Table 4 shows the IVl hue, heat resistance, and hot water resistance of the polycarbonate obtained.

table

Claims (5)

[Claims] (1) In the method of producing polycarbonate by melt polycondensation of bisphenols and diester carbonate, as bisphenols, adducts of 2,2-bis(4-hydroxyphenyl)propane and phenols or such adducts are used. A method for producing polycarbonate, characterized by using a mixture with phenols. (2) The reaction of the above adduct or mixture with the carbonic acid diester is carried out using a nitrogen-containing basic compound, an alkali metal compound and/or an alkaline earth metal compound, and a boric acid and/or a boric acid ester. The method for producing polycarbonate according to claim 1, characterized in that the method is carried out using a catalyst containing at least one type of compound. (3) In the method of producing polycarbonate by melt polycondensation of bisphenols and carbonic acid diester, the bisphenols include an adduct of 2,2-bis(4-hydroxyphenyl)propane and phenol, or an adduct of the adduct. The content of the acidic substance contained in the adduct or the mixture is p-
A method for producing polycarbonate, which comprises using an adduct or mixture treated with an alkali so that the concentration is 0.5 ppm or less in terms of sulfonic acid. (4) The method for producing polycarbonate according to claim 3, wherein the alkali treatment is carried out using an anion exchange resin containing nitrogen atoms. (5) The reaction of the above adduct or mixture with a carbonic acid diester is carried out using a nitrogen-containing basic compound, an alkali metal compound and/or an alkaline earth metal compound, and a boric acid and/or a boric acid ester. 4. The method for producing polycarbonate according to claim 3, wherein the method is carried out using a catalyst containing at least one type of compound.