JP2001031754A - Manufacture of polycarbonate resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a polycarbonate resin by a simplified process which is little in content of impurities, volatile impurities in particular, and excellent in thermal stability, color stability and hydrolysis resistance. SOLUTION: The method of manufacturing a polycarbonate resin comprises a melt polycondensation reaction of an aromatic dihydroxy compound and an aromatic carbonic acid diester in the existence of a polymerization catalyst, feeding the obtained polycarbonate to a twin-screw extruder with multi step vents, kneading a mixture solution of water and a catalyst deactivating agent with the polycarbonate and subjecting the mixing to a pressure reducing treatment. The polymerization catalyst is composed of 1×10-8 to 5×10-5 equivalent of an alkali metal compound and/or an alkaline earth metal compound and 1×10-5 to 5×10-3 equivalent of a nitrogen-containing basic compound per 1 mol of the aromatic hydroxy compound. The polycarbonate and the mixture solution are kneaded under an absolute pressure of 0.3 to 10 MPa at a temp. of 200 to 350 deg.C for 0.1 to 100 seconds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a polycarbonate resin, and more particularly to a method for producing a polycarbonate resin which has a very low content of impurities, particularly volatile impurities, and has a high thermal stability, a high color stability,
The present invention relates to a method for producing a polycarbonate resin having excellent hydrolysis resistance in a simplified process.

[0002]

2. Description of the Related Art Polycarbonate resins have excellent mechanical properties such as impact resistance and transparency, and are widely used for various purposes. As a method for producing a polycarbonate resin, an interface method in which a dihydroxy compound and phosgene are directly reacted, and a melting method in which a dihydroxy compound and a diester carbonate are transesterified under heating and reduced pressure are known.

[0003] The production of polycarbonate resin is usually carried out by kneading a polymerized polycarbonate. However, impurities in the final product of the polycarbonate, particularly volatile impurities such as raw material components and reaction by-products or solvents, are contained. Remains. Such a polycarbonate resin in which impurities remain has a problem in that a part thereof is thermally decomposed during melt molding to decrease the molecular weight, decrease the transparency, and cause coloring.

In order to solve such a problem, Japanese Patent Publication No. 5-2
No. 7,647 and Japanese Patent Publication No. 5-48162 propose a method of kneading and extruding a polycarbonate obtained by polymerization while adding water with a twin-screw extruder. But,
The effect of reducing volatile impurities was still low. Further, in the method of adding water, hydrolysis of polycarbonate may occur, and at present, a satisfactory solution has not yet been obtained. Further, in the case of a polycarbonate produced by a transesterification method, a step of adding a catalyst deactivator is necessary, and when the catalyst deactivator is not sufficiently dispersed in a polymer, hydrolysis is caused by adding water. May be further promoted.

[0005]

An object of the present invention is to provide a method for producing a polycarbonate resin, which has a very low content of impurities, especially volatile impurities, and has excellent heat stability, hue stability and hydrolysis resistance. An object of the present invention is to provide a manufacturing method for manufacturing a polycarbonate resin in a simplified process.

[0006]

According to the present invention, the above objects and advantages of the present invention are attained by melt-polycondensing an aromatic dihydroxy compound and an aromatic diester carbonate in the presence of a polymerization catalyst to obtain a polycarbonate. Is supplied to a twin-screw extruder equipped with a multistage vent, and the polycarbonate is kneaded with a mixed solution comprising water and a catalyst deactivator, and then subjected to a reduced pressure treatment. .

According to the method for producing a polycarbonate resin of the present invention, a polycarbonate resin having an extremely small content of impurities, particularly volatile impurities, can be produced in a simplified process, and the heat stability and hue during molding can be improved. A polycarbonate resin having excellent stability and hydrolysis resistance can be produced.

The polycarbonate used in the present invention is produced by subjecting an aromatic dihydroxy compound and an aromatic diester carbonate to melt polycondensation (ester exchange) in the presence of a polymerization catalyst.

As the aromatic diol compound used for the melt polycondensation, specifically, bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl)
Propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxy-
3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, bis (4-hydroxyphenyl) oxide, bis (3,5-dichloro-4-hydroxyphenyl) oxide , P, p'-dihydroxydiphenyl, 3,3'-
Dichloro-4,4'-dihydroxydiphenyl, bis (hydroxyphenyl) sulfone, resorcinol, hydroquinone, 1,4-dihydroxy-2,5-dichlorobenzene, 1,4-dihydroxy-3-methylbenzene, bis (4-hydroxy Examples thereof include phenyl) sulfide and bis (4-hydroxyphenyl) sulfoxide, and particularly preferred is 2,2-bis (4-hydroxyphenyl) propane.

Specific examples of the carbonic acid diester include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis (diphenyl)
Carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate and the like are used. Of these, diphenyl carbonate is particularly preferred.

Further, if necessary, the polycarbonate of the present invention may contain aliphatic diols such as ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and 1,10-decanediol. Examples of the dicarboxylic acids include succinic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, cyclohexanecarboxylic acid, and tereflutaic acid; oxyacids such as lactic acid, P-hydroxybenzoic acid, and 6-hydroxy-2-naphthoic acid It may contain an acid or the like.

The aromatic diester carbonate is used in an amount of 0.8 to 1.5 per mole of the aromatic dihydroxy compound.
Mole, preferably 0.95 to 1.1 mole, more preferably 1.0 to 1.05 mole.

In the melt condensation polymerization, a transesterification catalyst can be used to increase the polymerization rate when producing a polycarbonate by the transesterification reaction between the aromatic dihydroxy compound and the aromatic carbonate diester as described above.

As the catalyst, an alkali metal compound and / or an alkaline earth metal compound and a nitrogen-containing basic compound can be used.

Examples of the alkali metal compound used as a catalyst include hydroxides, bicarbonates, carbonates, acetates, nitrates, nitrites, sulfites, cyanates, thiocyanates, stearate salts of alkali metals. Borohydride, benzoate, hydrogen phosphate, bisphenol, phenol salt and the like.

Specific examples 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 nitrate, potassium nitrate, lithium nitrate, sodium nitrite, potassium nitrite, lithium nitrite, sodium sulfite, potassium sulfite, lithium sulfite, sodium cyanate, potassium cyanate , Lithium cyanate, sodium thiocyanate,
Potassium thiocyanate, lithium thiocyanate, sodium stearate, potassium stearate, lithium stearate, sodium borohydride, potassium borohydride, lithium borohydride, sodium phenylated borate, sodium benzoate, potassium benzoate, benzoate Examples thereof include lithium acid, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium salt, dipotassium salt, dilithium salt of bisphenol A, sodium salt, potassium salt, and lithium salt of phenol.

In the present invention, if desired, (a) an alkali metal salt of an ate complex of an element of Group 14 of the periodic table or (b) an oxoacid of an element of Group 14 of the periodic table may be used as the alkali metal compound of the catalyst. Can be used. Here, the elements of Group 14 of the periodic table refer to silicon, germanium, and tin.

The alkaline earth metal compound used as a catalyst includes, for example, hydroxides, bicarbonates, carbonates, acetates, nitrates, nitrites, sulfites, cyanates, thiocyanates of alkaline earth metals. , Stearates,
Examples include borohydride salts, benzoates, hydrogen phosphates, bisphenols, and salts of phenols.

Specific examples include calcium hydroxide, barium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, strontium carbonate, calcium acetate, barium acetate, strontium acetate, Calcium nitrate, barium nitrate, strontium nitrate, calcium nitrite, barium nitrite, strontium nitrite, calcium sulfite, barium sulfite, strontium sulfite, calcium cyanate, barium cyanate, strontium cyanate, calcium thiocyanate, barium thiocyanate, Strontium thiocyanate, calcium stearate, barium stearate, strontium stearate, calcium borohydride, barium borohydride, water Boron strontium, calcium benzoate, barium benzoate, strontium benzoate, calcium salts of bisphenol A, a barium salt,
Strontium salts, calcium salts of phenol, barium salts, strontium salts and the like can be mentioned.

The alkali metal compound or alkaline earth metal compound as the catalyst is used in an amount of 1 × 10 ^{-8 to} 5 × 10 ^-5 equivalents per mole of the aromatic diol compound. It is preferably used when A more preferable ratio is a ratio that is 5 × 10 ⁻⁷ to 1 × 10 ⁻⁵ equivalents with respect to the same standard.

If the amount of use is out of the above range, problems may be caused such as adverse effects on various physical properties of the obtained polycarbonate resin, and a high-molecular weight polycarbonate cannot be obtained due to insufficient transesterification reaction.

Here, the equivalents of the alkali metal compound and the alkaline earth metal compound referred to in the specification of the present application are defined as the sum of the valences of the alkali metal element or the alkaline earth metal element contained in one molecule of the catalyst and the number of moles of the catalyst. When one alkali metal element (monovalent) is contained in one catalyst molecule, one mole of the catalyst is equal to one equivalent of the catalyst, and one alkali earth metal element (divalent) is contained in one molecule. When included, one mole of catalyst equals two equivalents of catalyst. When two alkali metal elements (monovalent) are contained in one molecule of the catalyst, the catalyst 1
The mole equals 2 equivalents of catalyst.

Examples of the nitrogen-containing basic compound as a catalyst include, for example, tetramethylammonium hydroxide (Me ₄ NOH), tetraethylammonium hydroxide (Et ₄ NOH), tetrabutylammonium hydroxide (Bu ₄ NOH), benzyl Ammonium hydroxides having alkyl, aryl, alkylaryl groups such as trimethylammonium hydroxide (φ-CH ₂ (Me) ₃ NOH), hexadecyltrimethylammonium hydroxide, triethylamine, tributylamine, dimethylbenzylamine, hexadecyl Tertiary amines such as dimethylamine, or tetramethylammonium borohydride (Me ₄ NB
H ₄ ), basic salts such as tetrabutylammonium borohydride (Bu ₄ NBH ₄ ), tetrabutylammonium tetraphenylborate (Me ₄ NBPh ₄ ), and tetrabutylammonium tetraphenylborate (Bu ₄ NBPh ₄ ). it can.

The above-mentioned nitrogen-containing basic compound is preferably used in such a ratio that the amount of ammonium nitrogen atoms in the nitrogen-containing basic compound is 1 × 10 ^{−5 to} 5 × 10 ⁻³ equivalent per 1 mol of the aromatic diol compound. A more preferable ratio is a ratio that is 2 × 10 ^{−5 to} 5 × 10 ⁻⁴ equivalents with respect to the same standard. A particularly desirable ratio is 5 × 10 ^{−5 to} 5 × 10 ^{−4 with} respect to the same standard.
This is the equivalent ratio.

Here, the equivalent of the catalyst of the nitrogen-containing basic compound referred to in the present specification means the product of the total number of valencies of the basic nitrogen compound contained in one molecule of the catalyst and the number of moles of the catalyst. When one basic nitrogen element (monovalent) is contained in one molecule, one mole of the catalyst is equal to one equivalent of the catalyst. For example, tetramethylammonium hydroxide (Me ₄ NO
H) One mole equals one equivalent of catalyst.

In the polycondensation reaction of the present invention, at least one member selected from the group consisting of an oxo acid of Group 14 element of the periodic table and an oxide of the same element, if necessary, together with the above catalyst.
Various co-catalysts can be co-present.

By using these cocatalysts in a specific ratio, the terminal block reaction and the polycondensation reaction rate are not impaired, the branching reaction which is easily generated during the polycondensation reaction, or the foreign matter in the apparatus during the molding process is performed. Undesirable side reactions such as generation and burning can be more effectively suppressed.

In the present invention, the temperature and pressure at which the transesterification reaction between the aromatic dihydroxy compound and the carbonic acid diester is not particularly limited, and the reaction starts, and the monohydroxy compound produced by the reaction is quickly discharged out of the reaction system. Any conditions may be used as long as the temperature and the pressure can be removed, but a temperature of 150 ° C. to 200 ° C. and 4.0 × 10 ³ Pa
(30 mmHg) to 1.333 × 10 ⁴ Pa (100 m
mHg), the reaction temperature is increased according to the increase in the molecular weight of the polycarbonate with the progress of the reaction, and the reaction pressure is decreased.
The reaction is generally carried out at a temperature of 1.333 × 10 ² Pa (1 mmHg) or less.

More specifically, when the viscosity average molecular weight (Mv) of the polycarbonate is in the range of 1,000 to 2,000, the temperature is 150 to 220 ° C. and the viscosity is 4.0 × 10 ³ Pa (30
mmHg) to 1.333 × 10 ⁴ Pa (100 mmHg)
g) The reaction was carried out at a pressure of
In the region of 200-250 ° C., 1.333 × 10 ³ Pa
(10 mmHg) to 1.333 × 10 ⁴ Pa (100 m
mHg), and in the region where Mv exceeds 10,000, at 250 to 300 ° C. and 1.333 × 10 ² Pa (1
mmHg) or less. The unit of pressure used is absolute pressure unless otherwise specified.

In the present invention, there are no particular restrictions on the equipment and process used to produce a polycarbonate by transesterifying an aromatic dihydroxy compound and a carbonic acid diester, and conventionally known equipment and processes can be used. When the batch system is used, two reactors are usually installed in series, and the former is equipped with a rectification column using a stirring tank.
In the latter case, the reaction is carried out under different conditions using a stirred tank without a rectification column. In this case, the two are connected by a pipe equipped with a valve, and if necessary, the former reactant is transferred to the latter without contact with the outside air using equipment equipped with a pump for transferring the reaction solution, and the latter is used as desired. It is preferred to carry out the reaction up to the degree of polymerization.

When the reaction is carried out in a continuous system, usually two or more reactors are installed in series, adjacent reactors are connected by a pipe equipped with a valve, and a pump for transferring a reaction solution is provided if necessary. With the equipment provided, feed the raw material and catalyst continuously to the first reactor while maintaining each reactor under different conditions,
It is carried out by continuously withdrawing a polycarbonate having a desired degree of polymerization from the last reactor.

The molar ratio of the carbonic acid diester to the aromatic dihydroxy compound depends on the capacity of the rectification column, the conversion of the monomer in the reactor, and the OH of the polycarbonate to be obtained.
It varies depending on the amount of terminal groups, but is usually from 0.8 to 1.5, preferably from 0.95 to 1.1, more preferably from 1.0 to 1.05.
Is used.

There are no particular restrictions on the material of the equipment used in these facilities, but materials with a high iron content should be avoided, and nickel, stainless steel, etc. are usually preferably used.

The polycarbonate thus obtained is fed to a twin-screw extruder equipped with a multi-stage vent, and subjected to treatments such as addition and kneading of a catalyst deactivator, devolatilization with addition of water, and addition and kneading of additives to obtain excellent quality. In the present invention, the catalyst deactivator significantly lowers the activity of the polymerization catalyst, and in the present invention, when deactivating the polymerization catalyst in the polycarbonate, the melt polycondensation is carried out. After completion of the reaction, a mixture of water and a catalyst deactivator is simultaneously added to the polycarbonate using a twin screw extruder with a multistage vent. By simultaneously adding water and a catalyst deactivator as a mixed solution, the effect of deactivating the polymerization catalyst and the effect of removing volatile impurities can be simultaneously obtained, and a part of the devolatilization step can be omitted and simplified. In this process, a polycarbonate resin having extremely low content of impurities, particularly volatile impurities, and having excellent heat stability, hue stability, and hydrolysis resistance can be produced.

As the catalyst deactivator, JP-A-8-59975
The known agents described in No. 1 are effectively used, and among them, ammonium salts of sulfonic acid, phosphonium salts of sulfonic acid, and esters of sulfonic acid are preferable.

Further, esters, ammonium salts, and phosphonium salts of dodecylbenzenesulfonic acid, esters of p-toluenesulfonic acid, ammonium salts, phosphonium salts, esters of benzenesulfonic acid, ammonium salts, and phosphonium salts are preferred.

Examples of the sulfonic acid ester as a catalyst deactivator include methyl benzenesulfonate, ethyl benzenesulfonate, butyl benzenesulfonate, octyl benzenesulfonate, phenylbenzenesulfonate, methyl paratoluenesulfonate, and the like. Preferred examples include ethyl paratoluenesulfonate, butyl paratoluenesulfonate, octyl paratoluenesulfonate, and phenyl paratoluenesulfonate.

In the present invention, among these catalyst deactivators, tetrabutylphosphonium dodecylbenzenesulfonate and tetrabutylammonium p-toluenesulfonate are most preferably used.

The twin screw extruder used in the present invention has a kneading section,
Although a unit processing zone including a material seal portion and a vent portion is provided, the number of unit processing zones may be one, but it is preferable to have a plurality of unit processing zones. The number is preferably about 2 to 10.

The kneading unit is usually provided with a neutral kneading and / or a forward kneading and / or a reverse kneading in a screw configuration, whereby a mixture of polycarbonate, water and a catalyst deactivator is kneaded.

The material seal portion is located between the kneading portion and the vent portion, and has a function of maintaining a reduced pressure in the vent portion. Further, the material seal portion is constituted by one or more of reverse flight, seal ring, and reverse kneading.

In the kneading section, a paddle type stirring blade or the like is provided to knead the polycarbonate. The supply port of the mixed solution of water and the catalyst deactivator is preferably provided in the kneading section on the upstream side in the traveling direction of the polycarbonate.

A vent port is provided in the decompression section, and the inside of the decompression section is maintained at a reduced pressure by a vacuum pump or the like.

The amount of the mixture of water and the catalyst deactivator is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the polycarbonate. The ratio is more preferably 0.3 to 3 parts by weight, and even more preferably 0.3 to 2 parts by weight. If the amount of the mixture is less than 0.1 part by weight, the removal of volatile impurities is insufficient, while if it exceeds 5 parts by weight, the polycarbonate is hydrolyzed and the molecular weight may be reduced.

The composition of the mixture of water and the catalyst deactivator is 1 × water
It is preferred the catalyst deactivator is a ratio of 0.05 to 5 × 10 ⁵ parts by weight per ¹⁰⁶ parts by weight. The addition amount of the catalyst deactivator at this time, the addition amount of the catalyst deactivator to the polycarbonate resin obtained by melt polymerization, an alkali metal compound,
0.5 to 50 equivalents, preferably 0.5 to 10 equivalents, more preferably 0.8 to 5 equivalents per equivalent of the main polycondensation catalyst selected from alkaline earth metal compounds.
Use in equivalent proportions. Here, the equivalent of the catalyst deactivator represents the number of sites present in one molecule of the catalyst deactivator that can react with one valence of the catalyst metal. When one reactive site is present in one molecule, one mole is equal to one equivalent, and when two reactive sites are present, one mole is equal to two equivalents. This is usually 0.01 to 500 pp with respect to the polycarbonate resin.
It is equivalent to using at a rate of m.

In the present invention, the time for kneading the polycarbonate and the mixed solution comprising water and the catalyst deactivator is as follows:
It is defined by the average residence time of the polycarbonate in the kneading section. The kneading time per unit processing zone is preferably 0.05 to 20 seconds. In the case of an extruder having a plurality of unit processing zones, the kneading time is expressed as the total time for kneading the polycarbonate in the plurality of unit processing zones, and is preferably 0.1 to 100 seconds.

If the kneading time is shorter than this, the effect of removing impurities is reduced, and the kneading of the catalyst deactivator is not sufficient. If the kneading time is longer than this, the polycarbonate may be hydrolyzed to lower the degree of polymerization.

In the present invention, the addition of the catalyst deactivator as a mixed solution with water improves the uniform dispersibility in the polycarbonate, so that the catalyst can be deactivated in a short time. Decomposition can be effectively suppressed.

The temperature conditions for kneading the mixture of water and the catalyst deactivator with the polycarbonate are 200 ° C. to 350 ° C.
Preferably, the temperature is from 220 ° C to 300 ° C.
If the temperature of the polycarbonate is lower than 200 ° C., it is difficult to knead the polycarbonate with a mixture of water and the catalyst deactivator, while if it exceeds 350 ° C., the polycarbonate may be thermally decomposed.

The pressure conditions during the kneading of the polycarbonate and the mixed solution comprising water and the catalyst deactivator are from 0.3 to 10
It is preferably an absolute pressure of MPa. The reaction is preferably performed under a pressure of 0.7 to 5.0 MPa, 1.0 to 5.0 MPa, and more preferably 1.0 to 2.0 MPa.
When the kneading pressure is lower than 0.3 MPa, sufficient deaeration performance cannot be obtained, and when the kneading pressure is higher than 10 MPa, the production cost is increased and it is economically disadvantageous.

After kneading the polycarbonate, a mixed solution of water and a catalyst deactivator, the mixture is subjected to a reduced pressure treatment. In the decompression section, the water and volatile impurities existing in the polycarbonate in the mixed solution of water and the catalyst deactivator added in the kneading section are subjected to decompression treatment by a vacuum pump or the like and removed. A full flight is installed in the screw configuration at the vent. The decompression treatment conditions were 1.333 × 10 Pa (0.1 mmH
g) to 9.333 × 10 ⁴ Pa (700 mmHg), preferably 1.333 × 10 ² Pa (1 mmHg) to 6.
667 × 10 ⁴ Pa (500 mmHg) is used.

The residence time of the polycarbonate at the vent of the unit treatment zone is about 0.1 to 10 seconds.

By the above-described vacuum treatment, impurities remaining in the polycarbonate final product, particularly volatile impurities such as raw material components and reaction by-products or solvents, can be effectively removed. Also, for example, even if the added catalyst deactivator shown above contains a volatile compound or generates a thermal decomposition product by thermal decomposition, it can be removed at the same time by vacuum treatment.

When the twin-screw extruder with a multistage vent has a plurality of unit treatment zones, a mixed solution of water and a catalyst deactivator is added and kneaded in the first treatment zone, and water is added after the second treatment zone. Is preferably added and kneaded.
After kneading the polycarbonate and water in the second and subsequent treatment zones, it is preferable to perform a reduced pressure treatment.

The amount of water added after the second treatment zone is 100% of the polycarbonate treatment amount per unit treatment zone.
The ratio is preferably 0.1 to 5 parts by weight with respect to parts by weight.

The kneading time in the case of an extruder having a plurality of unit processing zones is, as described above, the time for kneading the polycarbonate in the presence of the mixed solution of water and the catalyst deactivator in the first processing zone, It is expressed as the sum of the time for kneading the polycarbonate in the presence of water after the second unit treatment zone. At this time, it is more preferable that the kneading time per each unit processing zone is 0.05 to 20 seconds, and the kneading time in the total processing zone is 0.1 to 100 seconds.

In the case of an extruder having a plurality of unit processing zones, the temperature condition for kneading after the second unit processing zone is 2
The temperature is more preferably from 00C to 350C, preferably from 220C to 300C.

In the case of an extruder having a plurality of unit processing zones, the pressure condition at the time of kneading the polycarbonate and water after the second unit processing zone is more preferably an absolute pressure of 0.3 to 10 MPa. Preferably 0.7 to 5.
The reaction is performed under a pressure of 0 MPa, 1.0 to 5.0 MPa, more preferably 1.0 to 2.0 MPa. When the kneading pressure is lower than 0.3 MPa, sufficient deaeration performance may not be obtained, and when the kneading pressure is higher than 10 MPa, the production cost is increased, which may be economically disadvantageous.

In the case of an extruder having a plurality of unit processing zones, the pressure reduction conditions after the second unit processing zone are preferably from 1.333 × 10 Pa (0.1 mmHg) to 9.333.
× 10 ⁴ Pa (700 mmHg), and more preferably 1.333 × 10 ² Pa (1 mmHg) to 6.66.
7 × 10 ⁴ Pa (500 mmHg) is used.

By applying the present invention, the step of adding and kneading the catalyst deactivator can be omitted and simplified compared with the conventional method of removing and kneading volatile impurities after adding and kneading the catalyst deactivator. In this process, a polycarbonate resin having extremely low content of impurities, particularly volatile impurities, and having excellent heat stability, hue stability, and hydrolysis resistance can be produced. In addition, the quality of the polycarbonate molded article thus produced is remarkably improved.

[0061]

According to the present invention, a polycarbonate as a reaction product is supplied to a twin-screw extruder equipped with a multi-stage vent, and the polycarbonate is kneaded with a mixed solution comprising water and a catalyst deactivator. By performing the decompression treatment, a polycarbonate resin having an extremely small content of impurities, particularly volatile impurities, can be produced in a simplified process, and the polymerization catalyst can be deactivated in a short time. Decomposition can be efficiently suppressed, and a polycarbonate resin having excellent heat stability, hue stability, and hydrolysis resistance during molding can be produced.

[0062]

Embodiments will be described below with reference to embodiments. The percentages, parts and ppm in the examples are% by weight, parts by weight or ppm unless otherwise specified. The physical properties of the polycarbonate obtained in the following Examples were measured as follows.

1. Intrinsic Viscosity and Viscosity Average Molecular Weight A methylene chloride solution containing 0.7 g of polycarbonate and 1 deciliter of methylene chloride was measured for intrinsic viscosity using an Ubbelohde viscometer, and the viscosity average molecular weight was determined by the following equation. [Η] = 1.23 × 10 ⁻⁴ M ^0.83 2. Amount of volatile impurities Phenol and diphenyl carbonate contained in a methylene chloride solution containing 100 g of polycarbonate and 1 liter of methylene chloride were extracted with acetonitrile and quantified by high performance liquid chromatography manufactured by Tosoh Corporation. 3. Pellet color Measured with a color difference meter manufactured by Nippon Denshoku Industries.

Example 1 Diphenyl carbonate was charged into a melting tank equipped with a stirrer at a ratio of 1.02 mol to 1 mol of 2,2-bis (4-hydroxyphenyl) propane, followed by purging with nitrogen. After dissolution.

Next, the melted mixture was provided with a rectification column, the internal temperature was 220 ° C., and the internal pressure was 1.333 × 10 ⁴ Pa (100 m
mHg), and 5 × 10 ⁻⁷ equivalents of bisphenol A disodium salt and 1 × 10 ⁻⁷ equivalents per mole of 2,2-bis (4-hydroxyphenyl) propane. ^-4 equivalents of tetramethylammonium hydroxide was added continuously, and the phenol formed was removed from the rectification column to carry out the reaction. The obtained reaction product was continuously extracted using a gear pump.

Then, the prepolymer was heated at an internal temperature of 250 ° C.
The internal pressure was continuously supplied to a vertical stirring tank maintained at 1.333 × 10 ³ Pa (10 mmHg). The resulting phenol was removed from the rectification column to carry out the reaction. The obtained reaction product was continuously extracted using a gear pump.

Next, the prepolymer was heated at an internal temperature of 270 ° C.
The internal pressure was continuously supplied to a horizontal uniaxial reaction vessel maintained at 1.333 × 10 ² Pa (1 mmHg). Polycarbonate having a viscosity average molecular weight of 15200 was continuously obtained by further polymerizing while removing generated phenol out of the system. This polycarbonate contained 180 ppm of phenol and 240 ppm of diphenyl carbonate.

Next, the polycarbonate was continuously supplied in a molten state to an interlocking twin-screw extruder having a liquid addition kneading section and a vent section in four stages. Bisphenol A used as a polymerization catalyst was added to the first liquid kneading section of the twin-screw ruder.
2 equivalents of dodecylbenzenesulfonate tetrabutylphosphonium salt per equivalent of disodium salt is 0.02 wt.
% Aqueous solution and continuously kneaded to the polycarbonate, then water is removed from the vent maintained at 2.0 × 10 ³ Pa (15 mmHg) to lose the activity of the polymerization catalyst and to remove some of the volatiles contained in the polymer. Was removed. Then the second
To the fourth liquid addition and kneading section each with respect to the polycarbonate.
wt% of water was continuously added and kneaded, and volatiles in the polycarbonate were removed by performing a vacuum treatment at 2.0 × 10 ³ Pa (15 mmHg) with a vent immediately after each liquid addition and kneading section,
Next, the product was extruded from a die through a gear pump after a twin-screw rudder, and pelletized by a pelletizer to obtain a final product polycarbonate.

Table 1 shows the measurement results of the residual phenol content, diphenyl carbonate content, viscosity average molecular weight, and hue b value in the obtained polycarbonate resin.

[0070]

[Table 1]

[Examples 2 to 12] The processing conditions of the twin-screw extruder shown in Tables 2 to 5, Examples 2 and 3 vary the amount of mixed liquid and water added, and Examples 4 and 5 vary the kneading time. In Examples 6 and 7, the amount of the catalyst deactivator was changed, Examples 8, 9, and 10 were changed in resin temperature, and Examples 11 and 12 were the same as Example 1 except that the pressure reduction conditions were changed. A polycarbonate resin was manufactured. Table 1 shows the measurement results of the residual phenol amount, diphenyl carbonate amount, viscosity average molecular weight, and hue b value in the obtained polycarbonate resin.
Are shown in FIGS.

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

[Table 4]

Example 13 A polycarbonate resin was produced in the same manner as in Example 1 except that the amount of tetrabutylammonium paratoluenesulfonate shown in Table 4 was used as a catalyst deactivator. Table 4 shows the measurement results of the residual phenol content, diphenyl carbonate content, viscosity average molecular weight, and hue b value in the obtained polycarbonate resin.

Example 14 A polycarbonate resin was produced in the same manner as in Example 1 except that the amount of butyl paratoluenesulfonate shown in Table 4 was used as a catalyst deactivator. Table 4 shows the measurement results of the residual phenol content, diphenyl carbonate content, viscosity average molecular weight, and hue b value in the obtained polycarbonate resin.

[Examples 15 and 16] Polycarbonate resins were produced in the same manner as in Example 1 except that the catalyst addition amount shown in Table 5 and the amount of the catalyst deactivator corresponding thereto were changed. Residual phenol amount, diphenyl carbonate amount, viscosity average molecular weight, hue b in the obtained polycarbonate resin
Table 5 shows the measurement results of the values.

[0078]

[Table 5]

[Examples 17 to 19] In Examples 17 to 18 of the twin-screw extruder processing conditions shown in Table 6, the amounts of the mixed liquid and water were changed, and Example 19 was performed except that the kneading time was changed. A polycarbonate resin was produced in the same manner as in Example 1. Table 6 shows the measurement results of the residual phenol amount, diphenyl carbonate amount, viscosity average molecular weight, and hue b value in the obtained polycarbonate resin.

[0080]

[Table 6]

[Comparative Examples 1 and 2] A polycarbonate resin was produced in the same manner as in Example 1 except that kneading was performed by adding only water without adding a catalyst deactivator. Residual phenol amount in the obtained polycarbonate resin, diphenyl carbonate amount,
Table 7 shows the measurement results of the viscosity average molecular weight and the hue b value.

[0082]

[Table 7]

[Comparative Example 3] Diphenyl carbonate was charged into a melting tank equipped with a stirrer at a ratio of 1.02 mol to 1 mol of 2,2-bis (4-hydroxyphenyl) propane, followed by purging with nitrogen. After dissolution.

Next, the molten mixture was provided with a rectification column, the internal temperature was 220 ° C., and the internal pressure was 1.333 × 10 ⁴ Pa (100 m
mHg), and 5 × 10 ⁻⁷ equivalents of bisphenol A disodium salt and 1 × 10 ⁻⁷ equivalents per mole of 2,2-bis (4-hydroxyphenyl) propane. ^-4 equivalents of tetramethylammonium hydroxide was added continuously, and the phenol formed was removed from the rectification column to carry out the reaction. The obtained reaction product was continuously extracted using a gear pump.

Then, the prepolymer was heated at an internal temperature of 250 ° C.
The internal pressure was continuously supplied to a vertical stirring tank maintained at 1.333 × 10 ³ Pa (10 mmHg). The resulting phenol was removed from the rectification column to carry out the reaction. The obtained reaction product was continuously extracted using a gear pump.

Then, the prepolymer was heated at an internal temperature of 270 ° C.
The internal pressure was continuously supplied to a horizontal uniaxial reaction vessel maintained at 1.333 × 10 ² Pa (1 mmHg). Polycarbonate having a viscosity average molecular weight of 15200 was continuously obtained by further polymerizing while removing generated phenol out of the system. This polycarbonate contained 180 ppm of phenol and 240 ppm of diphenyl carbonate.

Next, the polycarbonate was continuously supplied in a molten state to an interlocking twin-screw extruder having a liquid addition kneading section and five vent sections. Bisphenol A used as a polymerization catalyst was added to the first liquid kneading section of the twin-screw ruder.
Two equivalents of tetrabutylphosphonium dodecylbenzenesulfonate per equivalent of disodium salt were continuously added to the polycarbonate as a stock solution and kneaded.
A process for eliminating the activity of the polymerization catalyst was performed by performing a reduced pressure treatment with a vent kept at 0 ³ Pa (15 mmHg).
Subsequently, 1 wt% of water was continuously added to and kneaded with the polycarbonate in the second to fifth liquid addition and kneading sections, and 2.0 × 10 ³ Pa (15 mmH) was vented immediately after each liquid addition and kneading section.
Volatile substances in the polycarbonate were removed by performing a vacuum treatment in g), and then extruded from a die through a gear pump after a twin-screw rudder, and pelletized by a pelletizer to obtain a final polycarbonate product.

Table 8 shows the measurement results of the residual phenol content, diphenyl carbonate content, viscosity average molecular weight, and hue b value in the obtained polycarbonate resin.

[0089]

[Table 8]

[Comparative Example 4] A 4-stage meshing twin-screw extruder having a liquid addition section consisting of a unit treatment zone provided with a full flight having no kneading function as a screw structure and a vent section in a molten state with the polycarbonate in a molten state. The solution was continuously supplied, and the solution was added under the conditions shown in Table 9 and then subjected to a reduced pressure treatment. Residual phenol amount, diphenyl carbonate amount, viscosity average molecular weight, hue b in the obtained polycarbonate resin
Table 9 shows the measurement results of the values.

[0091]

[Table 9]

Continued on the front page (72) Inventor Toru Sawaki 2-1 Hinode-cho, Iwakuni-shi, Yamaguchi Pref. Teijin Limited Iwakuni Research Center (72) Inventor Katsushi Sasaki 2-1 Hinode-cho, Iwakuni-shi, Yamaguchi Pref. F term in the center (reference) 4J029 AA09 AB04 AB05 BB04A BB04B BB05A BB12A BB13A BF14A BG05X BG07X BG08X BG24X BH02 DB07 DB11 DB13 HC03 HC04A HC05A HC05B JA091 JA121 JA161 JA251 JB1 J3C1 J031 J031 J3C1 J031 KH05 LB05 LB07 LB08

Claims (13)

[Claims] 1. An aromatic dihydroxy compound and an aromatic diester carbonate are melt-polycondensed in the presence of a polymerization catalyst,
A method for producing a polycarbonate resin, comprising supplying the obtained polycarbonate to a twin-screw extruder equipped with a multi-stage vent, kneading the polycarbonate and a mixed solution comprising water and a catalyst deactivator, and subjecting the mixture to a reduced pressure treatment. . 2. A polymerization catalyst comprising 1 × 10 ^{−8 to} 5 × 10 ⁻⁵ equivalents of an alkali metal compound and / or an alkaline earth metal compound in an amount of 1 × 10 ^{−5 to} 1 mol of an aromatic dihydroxy compound. 2. The method according to claim 1, wherein the production method comprises up to 5 * 10 <^-3> equivalents of the nitrogen-containing basic compound. 3. The kneading of the polycarbonate and the mixed liquid,
200-350 ° C. under an absolute pressure of 0.3-10 MPa
The method is performed for 0.1 to 100 seconds.
3. The production method according to any one of 2. 4. The pressure reduction treatment is performed at 1.333 × 10 Pa
(0.1 mmHg) to 9.333 × 10 ⁴ Pa (700
(mmHg) under reduced pressure.
3. The production method according to any one of 3. 5. The catalyst deactivator according to claim 1, wherein at least one selected from the group consisting of ammonium salts of sulfonic acids, phosphonium salts of sulfonic acids and esters of sulfonic acids is used. The production method according to any one of the above. 6. A catalyst deactivator, which is an ester of dodecylbenzenesulfonic acid, an ammonium salt, a phosphonium salt, an ester of paratoluenesulfonic acid, an ammonium salt, a phosphonium salt, an ester of benzenesulfonic acid,
6. At least one member selected from the group consisting of ammonium salts and phosphonium salts is used.
The production method described in 1. 7. The method according to claim 1, wherein the catalyst deactivator is used in an amount of 0.5 to 50 equivalents per equivalent of the polymerization catalyst.
The method according to any one of the above. 8. The process according to claim 1, wherein the catalyst deactivator is used in an amount of 0.05 to 5 × 10 ⁵ parts by weight per 1 × 10 ⁶ parts by weight of water. 9. A twin screw extruder with a multi-stage vent, comprising: a kneading unit;
2. A unit treatment zone comprising a material seal portion and a vent portion, wherein the mixed solution is added to a kneading portion, and the polycarbonate and the mixed solution are kneaded.
9. The production method according to any one of items 1 to 8. 10. The mixed solution is used in an amount of 0.1 to 0.1 parts by weight per 100 parts by weight of polycarbonate per unit processing zone.
10. The composition according to claim 1, wherein the composition is used in an amount of 5 parts by weight.
The method according to any one of the above. 11. A twin-screw extruder with a multi-stage vent has a plurality of unit treatment zones, and a mixed solution of water and a catalyst deactivator is added and kneaded in a first treatment zone. The water is added and kneaded.
11. The method according to any one of items 10 to 10. 12. The method according to claim 11, wherein the polycarbonate per unit processing zone is 0.05 to 20 seconds, and the kneading time in the total processing zone is 0.1 to 100 seconds. . 13. The method according to claim 11, wherein after the second treatment zone, water is used in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the polycarbonate treated per unit treatment zone. The production method according to any one of the above.