JPH05287070A - Production of aromatic polycarbonate resin - Google Patents

Abstract

PURPOSE:To produce the title resin which contains no halogen, is excellent in thermal stability, and does not corrode a metal mold by synthesizing a low- mol.wt. oligomer by the interfacial reaction using a nonhalogen solvent, recovering the resulting low-melting oligomer in a molten state, and heating it to increase the degree of polymn. CONSTITUTION:An arom. polycarbonate resin contg. no halogen is produced by reacting an arom. polycarbonate oligomer having chloroformate groups with a monohydric phenol by the interfacial reaction using a nonhalogen solvent to give a phenylcarbonate-group-contg. arom. polycarbonate oligomer having a wt. average mol.wt. of 3,000 or lower, distilling out the solvent at a temp. higher then the m.p. of the latter oligomer to recover it in a moleten state without precipitating it, and heating it to cause transesterification to thereby increase the degree of polymn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a halogen-free aromatic polycarbonate, and the present invention relates to a method for producing an aromatic polycarbonate which does not pollute the environment.

[0002]

2. Description of the Related Art Aromatic polycarbonate resins have been widely used as engineering plastics for applications that take advantage of their good impact resistance, heat resistance, dimensional stability and transparency. As an industrial method for producing an aromatic polycarbonate resin, an interfacial polymerization method using phosgene is carried out, and as the solvent, a halogen-based solvent such as methylene chloride is mainly used because the solubility of the high molecular weight polycarbonate is high. Has been used. However, in the process using a halogen-based solvent, it is extremely difficult to remove the solvent remaining in the polymer because the solvent has a high polymer affinity. Therefore, it is necessary to dry the produced aromatic polycarbonate resin at high temperature for a long time, which is a problem in the production process. Further, in a low boiling point solvent such as methylene chloride, the solvent is liable to volatilize and pollute the environment, but in order to prevent this, there is a problem that the manufacturing cost of the plant becomes high.

On the other hand, as an interfacial polymerization method for a polycarbonate using a non-halogen solvent, a method using a hydrocarbon solvent such as toluene or xylene has been known so far. In this case, the molecular weight of the polymer is larger than a certain level. It is known that it will precipitate. Therefore, it is difficult to remove a by-product such as an inorganic salt taken in the precipitate because a molecular weight distribution is generated between the surface layer and the inside of the precipitate. For example, Schnell's'Chemis
try and Physics of Polyca
According to rbonates', when a polycarbonate is synthesized by an interfacial method using a xylene homolog as an organic solvent, the obtained polymer is a solvent-swollen white solid, and the obtained particulate polymer at 100 ° C. It is described that the halogen could not be completely removed by the alkali extraction.

In Japanese Patent Application Laid-Open No. 1-271426, a high-level process by a three-step method comprising 1) production of oligocarbonate using phosgene, 2) crystallization of the obtained oligocarbonate, and 3) solid-state polycondensation of crystallized oligocarbonate. A method for making a molecular weight aromatic polycarbonate resin is described. In this patent, it is stated that the solvent can be removed more easily than the usual interfacial method in order to remove the low molecular weight oligomer from the organic solvent. However, in the examples, a method of using a halogen-based solvent such as methylene chloride at the time of producing an oligomer is illustrated, and it is not described whether an aromatic polycarbonate resin containing no chlorine can be obtained.

Japanese Patent Laid-Open No. 11627/1990 describes a method of producing an aromatic polycarbonate by carrying out interfacial polymerization in a mixed solvent of an aromatic hydrocarbon and an alkane and / or a cycloalkane. However, in this method, it is necessary to use a special device (described as a kneader) to remove the inorganic salt and the halogen component from the solvent-swollen polycarbonate. Further, a method of once dissolving the produced polymer in methylene chloride and performing a washing step is also described in the specification, but it is difficult to produce an aromatic polycarbonate resin containing no halogen by this method. ..

Further, in JP-A-3-195726, a partially crystalline oligomer initial condensate is produced by an interfacial method using water and a non-halogen organic solvent in the first step, and melt or solid phase polymerization is performed in the second step. A method for obtaining a high molecular weight aromatic polycarbonate resin by carrying out a late condensation is disclosed.
This method is characterized in that when the oligomer produced in the first step is recovered, the partially crystallized oligomer is taken out by distilling off the solvent or using a poor solvent. However, when attempting to industrially carry out this method, it becomes a problem that the solvent swollen oligomer is difficult to handle in the case of distilling off the solvent, and in the case of reprecipitation, the treatment or separation step of the solvent. It costs too much.

As described above, in the conventional technology,
When a halogen solvent such as methylene chloride is used, there is a problem that halogen remains in the final product, and when a non-halogen solvent is used, the resulting oligomer is purified,
There was a problem with the recovery process. Therefore, a method for easily producing an aromatic polycarbonate containing no halogen component as an impurity has not been established so far.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the conventional method for producing an aromatic polycarbonate resin by the interfacial method, and simplifies the aromatic polycarbonate resin containing no halogen component. To provide a manufacturing method.

[0009]

Means for Solving the Problems As a result of earnest studies on a method for easily producing an aromatic polycarbonate containing no halogen compound, the present inventors have selected an oligomer having a low molecular weight by an interfacial method using a non-halogen organic solvent. The present invention has been achieved by solving the above-mentioned problems by recovering the obtained oligomer having a low melting point in a molten state by synthetically synthesizing, and subsequently increasing the molecular weight by a transesterification method in the post-polymerization step.

That is, in the present invention, a chloroformate group-containing aromatic polycarbonate oligomer is reacted with a monofunctional phenol to produce a phenyl carbonate group-containing aromatic polycarbonate oligomer, which is further prepared by a transesterification method. An oligomerization step of producing an aromatic phenyl carbonate oligomer having a weight average molecular weight of 3,000 or less by an interfacial reaction using a non-halogen solvent in the polymerization degree, and then distilling off the solvent at a temperature not lower than the melting point of the oligomer. And a polymerization step of taking out the oligomer in a molten state without precipitating the oligomer, and a polymerization step of further heating the oligomer obtained in the oligomer recovery step to raise the degree of polymerization. Aromatic polycarbonate containing no halogen The present invention relates to a resin manufacturing method.

The present invention will be described in detail below. As the non-halogen solvent in the present invention, any solvent can be used as long as it dissolves the aromatic polycarbonate oligomer and has low miscibility with water. As a solvent satisfying these conditions, for example, aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, isopropylbenzene, 1,3,5-trimethylbenzene, anisole, benzylethylether, ethylphenylether, diphenylether, methyl -T
-Ethyl solvents such as butyl ether and ketone solvents such as cyclohexanone, 2-hexanone, 2-heptanone and 3-heptanone. Of these, particularly preferred organic solvents are aromatic hydrocarbon solvents such as toluene and xylene, aromatic ether solvents such as anisole, and alicyclic ketone solvents such as cyclohexanone. Also,
These solvents may be used as a mixed solvent of two or more kinds, or a small amount of a halogen-based solvent may be added and used within a range not impairing the effects of the present invention.

The chloroformate group-containing aromatic polycarbonate oligomer used in the present invention is obtained by blowing phosgene into a mixture of an alkaline aqueous solution of an aromatic dihydroxy compound and an organic solvent. As the aromatic dihydroxy compound used as a raw material, those represented by the following general formula (I) are used.

[0013]

[Chemical 1]

In the formula, R ¹ and R ² are each independently a hydrogen atom,
Halogen, an alkyl group, an alkenyl group or an optionally substituted aryl group, X is an alkylene group represented by the following formula (II), a cycloalkyl group represented by the following formula (III), -O-,- CO-, -S-, -SO-, etc.

[0015]

[Chemical 2]

(Wherein R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms),

[0017]

[Chemical 3]

(Cycloalkylene group; n is an integer of 2 to 4) Particularly preferred as the aromatic dihydroxy compound is bis (4-hydroxyphenyl).
Methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxy) Phenyl) butane,
2,2-bis (4-hydroxyphenyl) butane, 1,
1-bis (4-hydroxyphenyl) pentane, 2,2
-Bis (4-hydroxyefnyl) pentane, 3,3-
Bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane,
2,2-bis (3-methyl-4-hydroxyphenyl)
Propane, 2,2-bis (3-ethyl-4-hydroxyphenyl) propane, 2,2-bis (3-sec-butyl-4-hydroxyphenyl) propane, 2,2-bis (3-isopropyl-4-) Hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, bis (4-hydroxyphenyl) phenylmethane, 1,1 -Bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4
-Hydroxyphenyl) -1-phenylpropane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) dibenzylmethane, 1,1
-Bis (4-hydroxyphenyl) -cyclopentane,
1,1-bis (4-hydroxyphenyl) -cyclohexane, 4,4′-dihydroxydiphenyl ether,
4,4'-dihitroxydiphenyl sulfide, 4,
4'-dihydroxydiphenyl sulfoxide, 4,4 '
Examples thereof include dihydroxydiphenyl sulfone and phenolphthalein.

These aromatic dihydroxy compounds may be used alone or as a mixture. When producing a chloroformate group-containing aromatic polycarbonate oligomer (aromatic polycarbonate oligomer containing a chloroformate group at the end), the molecular weight of the oligomer, the hydroxyl group and the chloroformate group in the oligomer can be controlled by controlling the reaction conditions. It is possible to arbitrarily adjust the ratio of.

The molecular weight of the chloroformate group-containing aromatic polycarbonate oligomer is 1,00 in terms of number average molecular weight.
Those of 0 or less are preferably used. If the molecular weight of the chloroformate group-containing aromatic polycarbonate oligomer is too large, the solubility in an organic solvent becomes extremely poor, which is not preferable. The number average molecular weight used here is obtained from the terminal group based on the definition given in the examples.

The proportion of chloroformate groups in all the terminal groups of the chloroformate-containing aromatic polycarbonate oligomer must be at least 50 mol%, preferably 55 mol% or more. When the proportion of the chloroformate group is less than 50 mol%, the proportion of hydroxyl groups in the terminal groups of the polycarbonate resin produced by the method of the present invention using this as a starting material is high, and the hydrolysis resistance is deteriorated, which is preferable. Absent.

Then, in the present invention, an aromatic polycarbonate oligomer having a chloroformate terminal group is reacted with an excess amount of a monofunctional phenol compound in the above-mentioned non-halogen solvent to obtain a phenyl carbonate group-containing aromatic polycarbonate. An oligomer (aromatic polycarbonate oligomer containing a phenyl carbonate group at the end) is produced. Examples of monofunctional phenol compounds used for such purposes include those represented by the general formula (IV)

[0023]

[Chemical 4]

(Wherein R is an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms which may be substituted,
m is 1 to 4. ) And the like. Specific examples include cresol, methoxyphenol, ter
Examples thereof include t-butylphenol, di-tert-butylphenol, amylphenol, tert-hexylphenol, di-tert-hexylphenol, octylphenol, cumylphenol, phenylphenol and xylenol.

In producing the phenyl carbonate group-containing aromatic polycarbonate oligomer, the chloroformate group-containing aromatic polycarbonate oligomer dissolved in the above-mentioned non-halogen organic solvent and an aqueous solution of an alkali salt of a monofunctional phenol compound are stirred. , Mix and react. At this time, a salt of a phenolic compound (phenolate) that reacts with the chloroformate group in the oligomer
Is 1 to 10 mol, preferably 1.05 to 3 mol, per mol of the chloroformate group. When the phenolate is less than 1 mol based on 1 mol of the chloroformate group in the oligomer, the reaction is not completed and unreacted chloroformate group remains, or the molecular weight of the oligomer increases during the reaction with the phenolate. There are problems such as doing. If the phenolate is 10 mol or more, it is industrially disadvantageous because the number of washing steps for removing the residual phenol compound from the organic solvent increases.

Furthermore, in the reaction of the phenol compound with the chloroformate group-containing aromatic polycarbonate oligomer, the amount of the phenol compound which is not an alkali salt is 10 mol or less, preferably 0.05 mol, per mol of the chloroformate group. It is also possible to exist in an amount of ~ 3 mol. Further, in the reaction of the chloroformate group-containing aromatic polycarbonate oligomer and the phenol compound, the pH of the aqueous phase in the reaction mixture is preferably 10-12. When the pH is lower than 10, the reaction progresses slowly because the amount of phenolate in the aqueous phase is small. on the other hand,
When the pH of the aqueous phase is 12 or more, the molecular weight of the oligomer tends to increase during the reaction, which is not suitable for producing an oligomer having a low melting point.

In the reaction of a chloroformate-containing aromatic polycarbonate oligomer with a phenol compound,
The emulsion may be in the W / O type or the O / W type, but the volume ratio of the water phase and the oil phase is 0.1: 1.0 to 2.0 :.
A range of 1.0 is preferred. Volume ratio of water phase and oil phase is 0.1
In the following cases, it becomes difficult to charge the alkali salt of the phenol compound in excess with respect to the chloroformate group in the oligomer. Further, when the volume ratio of the aqueous phase to the oil phase is 2 or more, the amount of the chloroformate group-containing aromatic polycarbonate oligomer charged per batch becomes small, resulting in poor productivity.

In carrying out the reaction between the chloroformate group-containing aromatic polycarbonate oligomer and the phenol compound, the reaction may be carried out without a catalyst, but if necessary, a known catalyst used in a usual interfacial method may be used. It can also be added. Specific examples of such a catalyst include tertiary amines such as triethylamine and tripropylamine, and quaternary salts of amines such as benzyltributylammonium chloride.

The weight average molecular weight of the phenyl carbonate group-containing aromatic polycarbonate oligomer must be 3,000 or less, preferably 2,000 or less. When the weight average molecular weight exceeds 3,000, the melting point of the obtained oligomer becomes 200 ° C. or higher, which is not preferable because it imposes a burden on the oligomer recovery step described later. Therefore, it is necessary to select the conditions for the oligomerization step of the present invention so that the molecular weight of the resulting oligomer falls within this range.

In the oligomer recovery step of the present invention, in order to remove the solvent from the oligomer solution and recover the oligomer, heating or reduced pressure is used according to a known method, and in some cases, heating and reduced pressure may be used in combination. As a device used in the oligomer recovery step, a known device used for usual solvent distillation can be used. Examples of such an apparatus include a tank-type evaporator, a thin-film evaporator, a horizontal continuous evaporator, and the like, and these may be used in combination as necessary.

In the oligomer recovery step of the present invention,
It is necessary to distill off the solvent at a temperature above the melting point of the oligomer. To do this, the temperature of the solution is 120 ° C to 220 ° C.
Is preferable, and more preferably 140 to 200 ° C.
Is. If the temperature of the solution is 120 ° C. or lower, the oligomer will continue to be concentrated below the melting point of the oligomer, and the oligomer will precipitate and gel, making handling difficult. Further, if the temperature of the solution exceeds 220 ° C. and the concentration is continued for a long time, the transesterification reaction proceeds and the phenol flows out, so that a step of separating the recovered solution becomes necessary, which is disadvantageous in the process.

The phenyl carbonate group-containing aromatic polycarbonate oligomer thus obtained is then subjected to a polymerization step. The polymerization method is not particularly limited, but melt polymerization is preferably used. When carrying out the polymerization reaction by the melting method, an aromatic dihydroxy compound represented by the above formula (I) may be added in addition to the phenyl carbonate group-containing aromatic polycarbonate oligomer. At this time, the amount of all phenyl carbonate groups is 1.0 to 2. with respect to 1 equivalent of all hydroxyl groups (the sum of the hydroxyl groups in the phenyl carbonate group-containing polycarbonate oligomer and the hydroxyl groups in the added aromatic dihydroxy compound).
It is preferably used in an amount of 0 equivalent, preferably 1.05 to 1.5 equivalent. When the equivalent of all phenyl carbonate groups is 1 equivalent or less relative to 1 equivalent of all hydroxyl groups,
The obtained high molecular aromatic polycarbonate resin has a large proportion of terminal hydroxyl groups, resulting in poor hydrolysis resistance. Further, when the equivalent of all phenyl carbonate groups is 2 equivalents or more relative to 1 equivalent of all hydroxyl groups, the melt polymerization rate becomes slow, which is not preferable.

In the polymerization step of the present invention, phloroglucin or 1,1,1-tris (4-hydroxyphenyl) is used.
It is also possible to form a branched polycarbonate by adding a trifunctional or higher polyfunctional compound such as ethane. further,
It is also possible to add an aromatic polyester polycarbonate resin by adding terephthalic acid or dicarboxylic acid such as isophthalic acid.

In the melt polymerization, the polymerization can be carried out without a catalyst, but a known melt polymerization catalyst may be added if necessary. A known transesterification catalyst or the like is used as the polymerization catalyst. Specifically, in addition to alkali metal or alkaline earth metal phenolates, carbonates, acetates, hydroxides, hydrides, phosphorus compounds such as phenylphosphoric acid, phenylphosphorous acid and metal salts thereof, and quinoline-5. −
Sulfonic acid, stearic acid monophenyl phosphate,
Organic acid catalysts such as 2-N-phenylaminobenzoic acid, tetramethylammonium-tetraphenylboranate,
Ammonium such as tetraphenylphosphonium-tetraphenylboranate, phosphonium borane salt catalyst, ammonium hydroxide such as tetrabutylammonium hydroxide and trimethylbenzylammonium hydroxide, quaternary ammonium such as dimethylphenylbenzylammonium chloride and benzyltributylammonium chloride Examples thereof include salts, iminoacetic acids such as iminodiacetic acid and ethylenediamine tetraacetate, amines such as 2-methylimidazole and dimethyl-4-aminopyridine, or salts thereof.

The melt polymerization reaction is carried out while gradually raising the temperature between 200 ° C and 340 ° C, and a more preferable temperature range is 220 ° C to 300 ° C. When the temperature is 200 ° C. or lower, the transesterification reaction is slow and the polymerization does not substantially proceed. The reaction temperature is 340
When the temperature is higher than 0 ° C, the decomposition reaction and other side reactions cannot be ignored, and the color tone of the obtained polymer deteriorates and the physical properties also deteriorate.

Further, in the melt polycondensation reaction, it is preferable to increase the temperature as the reaction progresses and increase the degree of pressure reduction to facilitate the outflow of desorbed substances such as phenol. The pressure of the reaction system is preferably normal pressure (760 mmHg) to 50 mmHg at the beginning of the melt polymerization reaction, and 10 mmHg or less at the beginning of the reaction. The polymer obtained by melt polymerization can be used as it is as a product, but when an aromatic polycarbonate resin having a higher degree of polymerization is required, the reaction or reaction in an extruder which is conventionally known or It is also possible to increase the degree of polymerization by using a reaction in the solid state. When performing solid phase polymerization, it is necessary to crystallize the prepolymer obtained by melt polymerization,
For this purpose, crystallization with a known solvent or crystallization by heating (see the above-mentioned Schnell document) can be used. Particularly, crystallization with a solvent is rapid and is preferably used.

The aromatic polycarbonate resin composition of the present invention thus obtained is substantially halogen-free. The halogen referred to in the present invention includes halogen in the solvent when a halogen-based solvent (methylene chloride, etc.) is used, as well as free C derived from phosgene as a raw material.
1 ^- ion (NaCl, HCl, etc.) and the like are included.

The term "substantially free of halogen" means that halogen is not detected by the usual ppm order detection method. Therefore, even if it contains a small amount of halogen, it corresponds to the case of containing substantially no halogen as long as it is less than 1 ppm. As such a case, a case where a trace amount of free Cl ⁻ ion (NaCl, HCl, etc.) derived from phosgene as a raw material is included.

As a method generally used for halogen detection, there is quantification by gas chromatography for halogen-containing volatile components such as methylene chloride and silver nitrate for free Cl ⁻ ions. There is a non-water titration method using, etc., but all of them usually have an accuracy of about 1 ppm. The aromatic polycarbonate resin obtained in the present invention may be added with a known heat stabilizer before use to improve its heat stability. As such a heat stabilizer, phosphoric acid and its esters, phosphorous acid and its esters, phosphorus compounds such as phosphonite, and phenolic antioxidants such as hindered phenols are used. These heat stabilizers may be used in combination of two or more kinds.

The aromatic polycarbonate resin obtained in the present invention may be modified with other resins, if necessary, or may be a filler such as glass fiber or carbon fiber, a flame retardant, a UV absorber, and a mold release agent. Agents and colorants may be added.

[0041]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following examples, unless otherwise specified, parts refer to parts by weight,% refers to% by weight, polycarbonate refers to an aromatic polycarbonate resin, and chloroformate group-containing oligomer refers to a chloroformate group at the end. A phenylcarbonate group-containing oligomer means an aromatic polycarbonate oligomer containing a phenylcarbonate group at the terminal.

The measurement items in the examples were determined according to the following methods. 1. Terminal group quantification a) Chloroformate group in oligomer The chloroformate group is decomposed with an excess amount of aniline, and the produced aniline hydrochloride is quantified with alcoholic potassium hydroxide. b) Terminal hydroxyl group in the oligomer After dissolving the oligomer in methylene chloride acidified with acetic acid, color is developed with titanium tetrachloride and quantified with a colorimeter at a wavelength of 546 nm. (Macromol. Chem., 88, 215.
(1965)) c) Terminal phenyl carbonate group in the oligomer After the alkali hydrolysis of the oligomer, the liberated phenol is quantified by liquid chromatography.

2. Measurement of molecular weight i) Number average molecular weight of oligomer The number average molecular weight was calculated from the analytical value obtained by quantifying the terminal group of

## EQU1 ## Number average molecular weight Mn = 2 × 10 ⁶ / (a + b +
c) a: Amount of chloroformate group in the oligomer (μeq /
g) b: Amount of terminal hydroxyl groups in the oligomer (μeq / g) c: Amount of terminal phenyl carbonate groups in the oligomer (μ
eq / g)

Ii) Weight average molecular weight Gel permeation chromatography (GP
The value of the weight average molecular weight measured in C) was used. (Using a calibration curve based on polystyrene standards)

Iii) Viscosity average molecular weight Intrinsic viscosity [η] (d) of a methylene chloride solution at 20 ° C.
1 / g) was measured using an Ubbelohde viscosity tube, and the viscosity average molecular weight was calculated using the following formula.

[Equation 2] [η] = 1.23 × 10 ⁻⁴ (Mv) ^0.83

Iv) Determination of chlorine component in polymer The volatile component containing halogen was determined by gas chromatography. Regarding free Cl ⁻ ions, the polymer was dissolved in a mixed solvent of methylene chloride / 2 v% hydrous acetone and then titrated with a hydrous acetone solution of silver nitrate.

Example 1 (1) Production of phenyl carbonate group-containing oligomer

[Table 1] Toluene solution of chloroformate group-containing oligomer ^{* 1} 200 parts * 1: Toluene solution of chloroformate group-containing oligomer synthesized from bisphenol A and phosgene Oligomer concentration 22.9 (wt%) Chloroformate group Concentration 0.94 (N) Hydroxyl concentration 0.20 (N) Toluene 260 parts was charged into a glass reactor equipped with a baffle plate, a stirrer and a thermometer, and the mixture was stirred and mixed, then distilled water 150 parts hydroxylated A mixed solution of 28 parts of sodium, 100 parts of phenol, and 0.4 parts of hydrosulfite was added to form an emulsion, and 0.05 part of triethylamine was added thereto and reacted at an internal temperature of 25 to 35 ° C. for 90 minutes. No solid precipitation was observed during this interfacial reaction. After completion of the reaction, stop the stirring and add 2
The phases were separated, the organic phase was recovered, and then washed with a 0.2N alkaline aqueous solution, a 0.1N hydrochloric acid aqueous solution, and distilled water in this order. The weight average molecular weight of the oligomer obtained here was 1,300.

The toluene solution obtained by the interfacial reaction was placed in a vertical reaction tank, heated at 140 ° C. under stirring and atmospheric pressure, and then gradually heated to 180 ° C. to finally obtain toluene. Was distilled off. The recovered phenyl carbonate group-containing oligomer was colorless and transparent, and had a low viscosity at 180 ° C., and was transferred in a molten state to be subjected to melt polymerization. (2) Production of high molecular weight polycarbonate

[Table 2] 5 parts of a phenyl carbonate group-containing oligomer, and 1.5 parts of bisphenol A were transferred to a reaction tank in which nitrogen was replaced, and the temperature was 220 ° C and 100 mm
After reacting with Hg for 2 hours, the temperature is gradually reduced while raising the temperature, and finally polycondensation reaction is performed at 290 ° C., 0.05 mmHg for 1 hour to obtain a viscosity average molecular weight of 21,50.
A colorless transparent polycarbonate of 0 was obtained. No chlorine component was detected in the obtained polycarbonate.

Example 2 (1) Preparation of phenyl carbonate group-containing oligomer 18 parts of sodium hydroxide and 62 parts of phenol were used.
The interface reaction between the chloroformate group-containing oligomer and the phenolate was carried out in the same manner as in Example 1 except that the parts were used. The weight average molecular weight of the obtained phenyl carbonate group-containing oligomer was 1,700.

(2) Production of high molecular weight polycarbonate A polycarbonate having a viscosity average molecular weight of 22,300 was obtained in the same manner as in Example 1 except that 5 parts of the phenyl carbonate group-specific oligomer and 1.2 parts of bisphenol A were used. .. No chlorine component was detected in the obtained polycarbonate.

Example 3 (1) Production of phenyl carbonate group-containing oligomer 10 parts of sodium hydroxide and 36 parts of phenol were used.
The interface reaction between the chloroformate group-containing oligomer and the phenolate was carried out in the same manner as in Example 1 except that the parts were used. The weight average molecular weight of the obtained phenyl carbonate group-containing oligomer was 2,100.

(2) Production of high molecular weight polycarbonate

[Table 3] 5 parts of phenyl carbonate group-containing oligomer 1.2 parts of bisphenol A were transferred to a nitrogen-substituted reaction tank, and 220 ° C, 100 mm
After reacting with Hg for 2 hours, the temperature is gradually reduced while increasing the temperature, and finally polycondensation reaction is performed at 270 ° C., 0.05 mmHg for 1 hour to obtain a viscosity average molecular weight of 14,50.
A colorless transparent polycarbonate of 0 was obtained. No chlorine component was detected in the obtained polycarbonate.

The low molecular weight polycarbonate thus obtained was crystallized in acetone vapor and then heated in an inert oven under a nitrogen stream at 180 ° C. for 2 hours, and then heated to 230 ° C. The reaction was continued for 15 hours. The viscosity average molecular weight of the obtained polycarbonate is 2
It was 7,800, and no chlorine component was detected.

Example 4 (1) Production of phenyl carbonate group-containing oligomer

[Table 4] Anisole solution of chloroformate group-containing oligomer ^{* 2} 300 parts * 2: Anisole solution of chloroformate group-containing oligomer synthesized from bisphenol A and phosgene Oligomer concentration 15.0 (wt%) Chloroformate group Concentration 0.70 (N) Hydroxyl concentration 0.15 (N) Anisole 150 parts Charged into a glass reactor equipped with a baffle, a stirrer and a thermometer, and mixed by stirring, then distilled water 130 parts hydroxylated A mixed solution of 18 parts of sodium, 62 parts of phenol and 0.4 part of hydrosulfite was added to form an emulsion, and 0.05 part of triethylamine was added thereto and reacted at an internal temperature of 25 to 35 ° C. for 90 minutes. No solid precipitation was observed during this interfacial reaction. After completion of the reaction, stop the stirring and add 2
The phases were separated, the organic phase was recovered, and then washed with a 0.2N alkaline aqueous solution, a 0.1N hydrochloric acid aqueous solution, and distilled water in this order. The weight average molecular weight of the oligomer obtained here was 2,500.

The oligomer solution obtained by the interfacial reaction was put into a vertical reaction tank and stirred at 100 mmHg for 1 mm.
Heat at 40 ° C, then gradually raise the temperature to 180
Anisole was distilled off by heating to ° C. The recovered phenyl carbonate group-containing oligomer was colorless and transparent, and had a low viscosity at 180 ° C., and was transferred in a molten state to be subjected to melt polymerization.

(2) Production of high molecular weight polycarbonate

[Table 5] 5 parts of phenyl carbonate group-containing oligomers 0.8 parts of bisphenol A were transferred to a nitrogen-substituted reaction tank, and 220 ° C, 100 mm
After reacting with Hg for 3 hours, the temperature is gradually reduced while raising the temperature, and finally polycondensation reaction is carried out for 1 hour at 290 ° C., 0.05 mmHg to give a viscosity average molecular weight of 21,50.
A colorless transparent polycarbonate of 0 was obtained. No chlorine component was detected in the obtained polycarbonate.

Example 5 (1) Production of phenyl carbonate group-containing oligomer

[Table 6] Xylene solution of chloroformate group-containing oligomer ^{* 3} 300 parts * 3: Xylene solution of chloroformate group-containing oligomer synthesized from bisphenol A and phosgene Oligomer concentration 13.2 (% by weight) Chloroformate group Concentration 0.78 (N) Hydroxyl concentration 0.17 (N) Xylene 100 parts was charged into a glass reactor equipped with a baffle plate, a stirrer and a thermometer, and mixed by stirring, then distilled water 130 parts hydroxylated A mixed solution of 13 parts of sodium, 44 parts of phenol, and 0.4 parts of hydrosulfite was added to form an emulsion, and 0.05 part of triethylamine was added thereto and reacted at an internal temperature of 25 to 35 ° C. for 90 minutes. No solid precipitation was observed during this interfacial reaction. After completion of the reaction, stirring was stopped and the oligomer solution was washed in the same manner as in Example 1. The weight average molecular weight of the oligomer obtained here was 1,100.

The oligomer solution obtained by the interfacial reaction was put in a vertical reaction tank and stirred at 100 mmHg for 1 mm.
Heat at 50 ℃, then gradually reduce the pressure, finally 1
Xylene was distilled off by reducing the pressure to 00 mmHg. The recovered phenyl carbonate group-containing oligomer was colorless and transparent, and was a liquid having a low viscosity at 150 ° C., which was transferred in a molten state to be subjected to melt polymerization.

(2) Production of high molecular weight polycarbonate

[Table 7] Phenyl carbonate group-containing oligomer 5 parts Bisphenol A 1.6 parts was transferred to a nitrogen-substituted reaction tank, and 220 ° C, 100 mm.
After reacting with Hg for 3 hours, the temperature is gradually reduced while raising the temperature, and finally, a polycondensation reaction is performed at 270 ° C., 0.05 mmHg for 1 hour to obtain a viscosity average molecular weight of 13,50.
A colorless transparent polycarbonate of 0 was obtained.

The prepolymer thus obtained was crystallized in acetone vapor and then heated in an inert oven at 180 ° C. for 2 hours in a nitrogen stream, after which 23
The temperature was raised to 0 ° C. and the reaction was continued for 15 hours. The viscosity average molecular weight of the obtained polycarbonate is 24,800,
No chlorine component was detected.

Example 6 (1) Production of phenyl carbonate group-containing oligomer

[Table 8] Cyclohexanone solution of chloroformate group-containing oligomer ^{* 4} 300 parts * 4: Cyclohexanone solution of chloroformate group-containing oligomer synthesized from bisphenol A and phosgene Oligomer concentration 14.7 (wt%) Chloroformate group Concentration 0.73 (N) Hydroxyl group concentration 0.16 (N) Cyclohexanone 140 parts was charged into a glass reactor equipped with a baffle plate, a stirrer and a thermometer, and the mixture was stirred and mixed, then distilled water 130 parts hydroxylated A mixed solution of 11 parts of sodium, 39 parts of phenol and 0.4 parts of hydrosulfite was added to form an emulsion, and 0.05 part of triethylamine was added thereto, and the mixture was reacted at an internal temperature of 25 to 35 ° C for 90 minutes. No solid precipitation was observed during this interfacial reaction. After completion of the reaction, stirring was stopped and the oligomer solution was washed in the same manner as in Example 1. The weight average molecular weight of the oligomer obtained here was 2,200.

The oligomer solution obtained by the interfacial reaction was placed in a vertical reaction tank and stirred at 100 mmHg for 1
Heat at 40 ° C, then gradually depressurize to a final 180
Cyclohexanone was distilled off by heating to ° C. The recovered phenyl carbonate group-containing oligomer was colorless and transparent, and had a low viscosity at 180 ° C., and was transferred in a molten state to be subjected to melt polymerization.

(2) Production of high molecular weight polycarbonate

[Table 9] Phenyl carbonate group-containing oligomer 5 parts Bisphenol A 1.0 part was transferred to a nitrogen-substituted reaction tank, and the temperature was 220 ° C and 100 mm.
After reacting with Hg for 3 hours, the temperature is gradually reduced while raising the temperature, and finally, a polycondensation reaction is performed at 280 ° C., 0.05 mmHg for 1 hour to obtain a viscosity average molecular weight of 15,70.
A colorless transparent polycarbonate of 0 was obtained.

The prepolymer thus obtained was crystallized in acetone and then heated in an inert oven under a nitrogen stream at 180 ° C. for 2 hours and then at 230 ° C.
The temperature was raised to and the reaction was continued for 15 hours. The viscosity average molecular weight of the obtained polycarbonate was 29,300, and chlorine component was not detected.

Comparative Example 1 (Production of phenyl carbonate group-containing oligomer) In the same manner as in Example 1, a phenyl carbonate group-containing oligomer was produced by an interfacial method using toluene as an organic solvent. The obtained toluene solution was placed in a vertical reaction tank and heated at 100 mmHg and 80 ° C. with stirring,
Thereafter, the pressure was gradually reduced and finally heated to 110 ° C. to distill off toluene. The recovered phenyl carbonate group-containing oligomer was a white sticky mass and was difficult to handle.

Comparative Example 2 (Production of phenyl carbonate group-containing oligomer) A chloroformate group-containing oligomer was prepared in the same manner as in Example 4 except that the amount of sodium hydroxide was 20 parts and the amount of phenol was 23 parts. An interfacial reaction with phenolate was performed. The weight average molecular weight of the obtained phenyl carbonate group-containing oligomer was 4,500.

The oligomer solution obtained by the interfacial reaction was placed in a vertical reaction tank and stirred at 100 mmHg, 1
Heat at 40 ° C, then gradually raise the temperature to 180
Anisole was distilled off by heating to ° C. The recovered phenyl carbonate group-containing oligomer was a white sticky mass and was difficult to handle.

[0068]

Since the aromatic polycarbonate resin produced by the method of the present invention contains substantially no halogen, it has excellent thermal stability and does not cause problems such as corrosion of the mold during molding. Therefore, when used in applications where aromatic polycarbonate resins have been used,
It is possible to obtain high quality products. Examples of specific applications include precision molded parts such as chassis of printers, personal computers, word processors, cameras, and structural members such as tricycles and prams that require strength.
Optical elements such as D, optical disks, optical fibers, lenses, glasses, glass substitutes such as windows of trains, cars, buildings, windshields of motorcycles, roof parts of carports, lamp covers, etc., and baby bottles , Bottles for medicines and drinks, containers for drinking water tanks, and films for packaging materials and tapes. In addition to the above, it can be suitably used in combination with other resins as a polymer alloy, or as a binder resin for electrophotographic photoreceptors and thermal transfer recording.

Further, in the method for producing an aromatic polycarbonate resin of the present invention, since a halogen-based solvent such as methylene chloride is not used, there is no fear of polluting the environment.

Claims (1)

[Claims] 1. A chloroformate group-containing aromatic polycarbonate oligomer is reacted with a monofunctional phenol to produce a phenyl carbonate group-containing aromatic polycarbonate oligomer, which is further subjected to a high degree of polymerization by a transesterification method. In doing so, an oligomerization step of producing an aromatic phenyl carbonate oligomer having a weight average molecular weight of 3,000 or less by an interfacial reaction using a non-halogen solvent, and then distilling the solvent at a temperature higher than the melting point of the oligomer And a polymerization step in which the oligomer obtained in the oligomer recovery step is further heated to increase the degree of polymerization. A method for producing an aromatic polycarbonate resin which does not contain.