JPH06192413A - Production of aromatic polycarbonate - Google Patents

Abstract

PURPOSE:To efficiently produce several kinds of arom. polycarbonates having different mol.wts., processibilities, and mechanical characteristics simultaneously on a single production line. CONSTITUTION:A soln. obtd. by dissolving at least one arom. dihydroxy compd. in an aq. soln. of an alkali or alkaline earth metal salt is reacted with a carbonyl halide compd. in the presence of a polymn. catalyst, a mol.-wt.- adjusting agent, and an org. solvent. These raw materials are continuously fed into a reactor comprising at least three reaction vessels installed in series, where the reaction is carried out under such conditions that the dwell time in each vessel is kept constant and that the component dwelling in the reactor is continuously taken out of at least two arbitrarily selected vessels including the last vessel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aromatic polycarbonate, more specifically, it has excellent heat resistance and transparency.
The present invention relates to a method for simultaneously and efficiently producing aromatic polycarbonates having various molecular weights and different types of varieties in a single production line.

[0002]

2. Description of the Related Art Aromatic polycarbonates differ in mechanical properties and moldability depending on their molecular weight. Low molecular weight ones have excellent moldability, and thin and precise molding is possible. High molecular weight ones are applied to molded products that require impact strength. As described above, it is necessary to produce aromatic polycarbonates having various molecular weights according to various uses.

Conventionally, a method for producing an aromatic polycarbonate by reacting an alkaline aqueous solution of an aromatic dihydroxy compound with a carbonyl halide compound has been known. Generally, an alkaline aqueous solution of an aromatic dihydroxy compound and a carbonyl halide compound are combined with each other. , A method of reacting in the presence of an organic solvent to form a low-molecular-weight polycarbonate oligomer having a haloformate group, and then polymerizing the polycarbonate oligomer using a polymerization catalyst (two-step method); The method can be roughly classified into a method (one-step method) in which an alkali aqueous solution of an aromatic dihydroxy compound and a carbonyl halide compound are reacted to successively perform a haloformate reaction and a polymerization reaction.

An aromatic dihydroxy compound and a carbonyl halide compound are reacted in the presence of an organic solvent,
Examples of the two-step method of forming a low-molecular-weight polycarbonate oligomer having a haloformate group and then polymerizing the polycarbonate oligomer using a polymerization catalyst include, for example, an alkaline aqueous solution of dihydric phenol, phosgene, an organic solvent and a cooled second The reaction product mixture in the reactor was adjusted to a concentration of 55 to 1 in the aqueous dihydric phenol solution
Introduced into the first reactor in an amount of 50 g / l,
A method for producing a polycarbonate oligomer, which comprises reacting at 25 ° C. for 0.5 to 20 seconds and subsequently in a second reactor at 10 to 30 ° C. for 1 to 20 minutes (JP-A-62-167321). ) Or a part of the reaction product mixture passes outside the reaction tube, and the rest of the reaction product mixture passes in a turbulent state from one mouth to the other mouth, A method in which an alkaline aqueous solution of a dihydric phenol is reacted with phosgene in the presence of an organic solvent, the obtained reaction mixture is combined with the above-mentioned part of the reaction mixture, and then further reacted (JP-A-62- 235322), and further, from one end of the reaction tower, an aqueous alkali solution of dihydric phenol, phosgene, 0.3 of the aqueous alkali solution.
˜1.0 volume organic solvent and cooled reaction mixture to a dilute phenol concentration of 55% total alkaline aqueous solution.
Continuous feeding at a rate of ~ 150 g / l
A continuous process for producing a polycarbonate oligomer, characterized in that the reaction is carried out at -25 ° C (JP-A-62-2673).
24).

However, in any of these methods, after the aromatic polycarbonate oligomer is produced, it is converted into an aromatic polycarbonate by adding a molecular weight regulator and a polymerization catalyst. By changing the amount of the molecular weight modifier added after producing the aromatic polycarbonate oligomer, an aromatic polycarbonate having a molecular weight according to the application can be synthesized. For that purpose, it is necessary to install a separate polymerization reactor for each product type, or to switch the operation when there is no multiple polymerization reactors. Inevitably, it becomes inefficient and requires a lot of effort.

On the other hand, as a method (one-stage method) for producing an aromatic polycarbonate by adding a polymerization catalyst and a molecular weight modifier at the time of the reaction between an aromatic dihydroxy compound and a carbonyl halide, a bisphenol mixture is prepared using a packed column. A method characterized by bringing an organic solvent and phosgene into contact with water containing a hydroxide selected from caustic soda or caustic potash, and setting the residence time in the packed column to 20 to 240 seconds (Japanese Patent Publication No. 41-4352). , Supplying a liquid aqueous phase and an organic phase, a gas phase containing phosgene to a reactor having a packing in the presence of an amine or a salt thereof, and further separating the reaction mixture leaving the last reactor into a liquid phase and a gas phase. Then, a method for producing a polymeric linear polycarbonate comprising isolating a reaction product from a liquid phase (Japanese Patent Laid-Open No. 47-14297), and several reactions Performed at a rate of 1 to 50 m / sec by supplying a mixture of an alkaline aqueous solution of an organic dihydroxy compound and an amine or amine salt aqueous solution, and introducing phosgene at a rate of 30 to 300 m / sec for condensation. A continuous process for producing a polymeric linear polycarbonate, which comprises contacting with an organic solvent and then carrying out condensation in a second reaction zone by a two-phase interfacial method (JP-A-49-116195). A method for producing an aromatic polycarbonate by interfacial condensation at a high temperature in the presence of a polymerization catalyst under the condition that the OH concentration of an aqueous phase is regulated using a group chlorinated hydrocarbon as a solvent (Japanese Patent Laid-Open No. 12259/1975)
No. 5) is known.

However, the products obtained by these methods are also only aromatic polycarbonates having a molecular weight determined by the amount of the molecular weight regulator added at the beginning. However, it is necessary to install a dedicated facility for each, or change the amount of the molecular weight regulator added and restart the operation. As described above, in the prior art, a method for efficiently producing aromatic polycarbonates having various molecular weights and different kinds of varieties in a single production line has not been found.

[0008]

DISCLOSURE OF THE INVENTION The present invention has excellent heat resistance and transparency, has various molecular weights, and aromatic polycarbonates of different kinds are produced in a single production line.
At the same time, the task is to manufacture efficiently.

[0009]

As a result of intensive studies to solve the above problems, the present inventors have found that an alkali metal or alkaline earth metal base aqueous solution of at least one aromatic dihydroxy compound and a carbonyl halide compound are used. ,
When producing an aromatic polycarbonate by reacting in the presence of a polymerization catalyst, a molecular weight modifier, and an organic solvent, at least three tank-type reactors connected in series are continuously supplied to carry out the reaction, and The present invention has been completed by finding that the above problems can be solved by continuously collecting the retained components in two or more arbitrary tanks including the final tank while keeping the respective residence times constant.

That is, in the present invention, an alkali metal or alkaline earth metal base aqueous solution of at least one aromatic dihydroxy compound is reacted with a carbonyl halide compound in the presence of a polymerization catalyst, a molecular weight modifier and an organic solvent. In producing an aromatic polycarbonate, the above substances are continuously supplied to at least three tank-type reactors connected in series to carry out a reaction, and the final tank is kept at a constant residence time in each reaction tank. A method for producing an aromatic polycarbonate, which comprises continuously recovering the retained components in two or more arbitrary tanks containing the aromatic polycarbonate.

The method of the present invention is carried out under a completely mixed reaction condition in a tank reactor which is efficiently stirred, and the progress of the polymerization reaction can be changed by adjusting the residence time and the amount of catalyst. Therefore, in a continuous reaction, a steady state can be formed at any stage in the process from the aromatic polycarbonate oligomer to the final molecular weight. Therefore, according to the method of the present invention, aromatics having various molecular weights up to the final molecular weight determined by the amount of the molecular weight regulator can be adjusted by adjusting the number of tank reactors for the polymerization reaction after haloformate, the residence time and the amount of catalyst. Polycarbonate can be recovered from each polymerization tank, and it becomes possible to efficiently produce several kinds of aromatic polycarbonate simultaneously in a single production line.

The present invention will be described in detail below. The aromatic dihydroxy compound used in the present invention is a compound represented by the following formula (1) or (2).

HO-Ar1-X-Ar2-OH (1) HO-Ar3-OH (2) In the above formula, Ar1, Ar2 and Ar3 are each a monocyclic divalent aromatic group, that is, a phenylene group or a substituted group. A substituted phenylene group having a group, and as the substituent,
Examples thereof include a halogen atom, a nitro group, an alkyl group, a cycloalkyl group, an alkenyl group, a hydrocarbon group such as an aralkyl group or an aryl group, and an alkoxy group.

Both Ar1 and Ar2 are preferably p-phenylene group, m-phenylene group or o-phenylene group, or one is p-phenylene group and the other is m-phenylene group or o-phenylene group. , Especially A
Both r1 and Ar2 are preferably p-phenylene groups. X is a linking group that connects Ar1 and Ar2, and is a single bond or a divalent hydrocarbon group, and further -O.
It may be a group containing an atom other than carbon and hydrogen, such as-, -S-, -SO-, -SO2-, -CO-. The divalent hydrocarbon group means a saturated hydrocarbon group such as methylene, ethylene, 2,2-propylidene, cyclohexylidene,
Examples thereof include an alkylidene group having a substituent such as cyclohexylidene, but also include a group substituted with an aryl group and the like, and a hydrocarbon group containing an aromatic group or other unsaturated hydrocarbon group. May be.

Specific examples of the aromatic dihydroxy compound include bis (4-hydroxyphenyl) methane and 1,1-
Bis (4'-hydroxyphenyl) ethane, 1,2-bis (4'-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) -1-naphthylmethane, 1,1-bis (4'-hydroxyphenyl) -1-phenylethane,
2,2-bis (4'-hydroxyphenyl) propane ["bisphenol A"], 2- (4'-hydroxyphenyl) -2- (3'-hydroxyphenyl) propane, 2,2-bis (4'- Hydroxyphenyl) butane, 1,1-bis (4′-hydroxyphenyl) isobutane, 2,2-bis (4′-hydroxyphenyl) octane, 2,2-bis (3′-methyl-4′-hydroxyphenyl) Propane, 2,2-bis (3'-ethyl-
4'-hydroxyphenyl) propane, 2,2-bis (3'-n-propyl-4'-hydroxyphenyl) propane, 2,2-bis (3'-isopropyl-4'-hydroxyphenyl) propane, 2, 2-bis (3'-s
ec-butyl-4′-hydroxyphenyl) propane,
2,2-bis (3′-tert-butyl-4′-hydroxyphenyl) propane, 2,2-bis (3′-cyclohexyl-4′-hydroxyphenyl) propane, 2,
2-bis (3'-allyl-4'-hydroxyphenyl)
Propane, 2,2-bis (3'-methoxy-4'-hydroxyphenyl) propane, 2,2-bis (3 ', 5'
-Dimethyl-4'-hydroxyphenyl) propane,
2,2-bis (2 ', 3', 5 ', 6'-tetramethyl-4'-hydroxyphenyl) propane, 2,2-bis (3'-chloro-4'-hydroxyphenyl) propane, 2, 2-bis (3 ', 5'-dichloro-4'-hydroxyphenyl) propane, 2,2-bis (3'-bromo-4'-hydroxyphenyl) propane, 2,2-bis (3', 5 '-Dibromo-4'-hydroxyphenyl) propane, 2,2-bis (2 ', 6'-dibromo-
3 ', 5'-dimethyl-4'-hydroxyphenyl) propane, bis (4-hydroxyphenyl) cyanomethane, 1-cyano-3,3-bis (4'-hydroxyphenyl) butane, 2,2-bis (4 Bis (hydroxyaryl) alkanes such as'-hydroxyphenyl) hexafluoropropane,

1,1-bis (4'-hydroxyphenyl) cyclopentane, 1,1-bis (4'-hydroxyphenyl) cyclohexane, 1,1-bis (4'-hydroxyphenyl) -3,3,5 -Bis (hydroxyaryl) cycloalkanes such as trimethylcyclohexane, 1,1-bis (4'-hydroxyphenyl) cycloheptane and 2,2-bis (4'-hydroxyphenyl) adamantane, 4,4'-dihydroxydiphenyl ether , 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, ethylene glycol bis (4-hydroxyphenyl) ether and other dihydroxydiaryl ethers, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxy-3 Dihydroxy such as 3'-dimethyldiphenyl sulfide Aryl sulfides, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide and other dihydroxydiaryl sulfoxides, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy- Dihydroxydiarylsulfones such as 3,3′-dimethyldiphenylsulfone, bis (4-hydroxyphenyl) ketone, bis (4
Bis (hydroxyaryl) ketones such as -hydroxy-3-methylphenyl) ketone,

Further, 6,6'-dihydroxy-3,
3,3 ', 3'-Tetramethylspiro (bis) indane ["spiroindane bisphenol"], trans-
2,3-bis (4'-hydroxyphenyl) -2-butene, 9,9-bis (4'-hydroxyphenyl) fluorene, 3,3-bis (4'-hydroxyphenyl) -2
-Butanone, 1,6-bis (4'-hydroxyphenyl) -1,6-hexanedione, 1,1-dichloro-
2,2-bis (4'-hydroxyphenyl) ethylene,
1,1-dibromo-2,2-bis (4′-hydroxyphenyl) ethylene, 1,1-dichloro-2,2-bis (5′-phenoxy-4′-hydroxyphenyl) ethylene, α, α, α ', Α'-Tetramethyl-α, α'-
Bis (4-hydroxyphenyl) -p-xylene, α,
α, α ', α'-tetramethyl-α, α'-bis (4-
Hydroxyphenyl) -m-xylene, 4,4′-dihydroxybiphenyl and the like can be mentioned. In addition to the above aromatic dihydroxy compounds, hydroquinone, resorcin, etc. are also used. You may use these individually or in mixture of 2 or more types. The aromatic dihydroxy compound used particularly preferably in the present invention is bisphenol A. Further, bisphenols (aromatic dihydroxy compounds) containing an ester bond produced by reacting 2 mol of bisphenol A with 1 mol of isophthaloyl chloride or terephthaloyl chloride are also useful.

The alkali metal or alkaline earth metal base (hereinafter abbreviated as base) used in the present invention is an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide, potassium hydroxide or calcium hydroxide. Etc.,
From the viewpoint of easy availability, sodium hydroxide and potassium hydroxide are preferable, and sodium hydroxide is particularly preferable.

The amount of the base used is preferably about 1.0 to 1.5 times, and more preferably about 1.25 to 1.45 times the equivalent of the aromatic dihydroxy compound. If the amount is less than 1.0 times the equivalent amount of the aromatic dihydroxy compound,
The haloformate of the aromatic dihydroxy compound does not proceed well and hydrolysis of the supplied carbonyl halide occurs. When the amount is more than 1.5 times the equivalent amount of the aromatic dihydroxy compound, the carbonyl halide and / or the haloformate group derived therefrom is hydrolyzed by the action of an excessive base, and further the aromatic polycarbonate formed. It is not preferable because even the breaking of the carbonate bond of the oligomer and the aromatic polycarbonate occurs. The base is usually used in the form of an aqueous solution, but it is preferable to dissolve the aromatic dihydroxy compound in this aqueous solution and use it in the reaction. Since the basic aqueous solution of the aromatic dihydroxy compound is generally easily colored, one or more reducing agents such as sodium sulfite, hydrosulfite, and sodium borohydride may be added as an antioxidant and adjusted. .

As the water for preparing the basic aqueous solution of the aromatic dihydroxy compound, distilled water, ion-exchanged water or the like may be used, but in the present invention, the washing water or the reaction obtained when the aromatic polycarbonate is produced is used. It is preferable to use the water as it is or as a mixture with other water. When water of reaction or washing water is used, the concentration of the inorganic salt in the water may be 0.3 to 20% by weight with respect to the aromatic dihydroxy compound, and the solubility of the aromatic dihydroxy compound in water is no problem. Even if it is considered, there is no problem if it is 0.3 to 15% by weight.

As the inorganic salt, sodium chloride, sodium bromide, sodium iodide, sodium carbonate, sodium hydrogen carbonate, potassium chloride, potassium bromide, potassium iodide, potassium carbonate, potassium hydrogen carbonate, potassium sodium carbonate, chloride Calcium, calcium carbonate,
Examples thereof include alkali metal or alkaline earth metal hydrochlorides or carbonates such as calcium hydrogen carbonate. Normally,
It is sodium chloride or potassium chloride that is produced as a by-product in a large amount during the production process of the aromatic polycarbonate.

The presence of an inorganic salt in the reaction water beforehand means that
No influence is exerted on the hydrolysis amount of carbonyl halide during the reaction, the average molecular weight of the aromatic polycarbonate oligomer produced, and the residual amount and the average molecular weight of the unreacted end groups of the aromatic polycarbonate produced by the polymerization of the oligomer. Don't give. However, when 20% by weight or more of the inorganic salt is present in the reaction water with respect to the aromatic dihydroxy compound, the solubility of the aromatic dihydroxy compound is significantly reduced. However, in this case, an aromatic polycarbonate having a wide molecular weight distribution tends to be produced, which is not preferable. In the present invention, an aromatic polycarbonate having a regular molecular weight distribution has a polydispersity index (weight average molecular weight / number average molecular weight) of about 1.9 or more and less than 3.0, preferably 1.9 or more and less than 2.8. Represents an aromatic polycarbonate.

The amount of water used to prepare the aqueous solution containing the aromatic dihydroxy compound is such that the aromatic dihydroxy compound and the aromatic dihydroxy compound are present in the presence of about 1.0 to 1.5 equivalents of the base. It is the minimum amount required for complete dissolution. When the amount of water is less than this amount, the aromatic dihydroxy compound is not completely dissolved and the aromatic dihydroxy compound in the solid state is dissolved during the phosgenation reaction, so that an aromatic polycarbonate having a wide molecular weight distribution is obtained. It is also not preferable because the aromatic dihydroxy compound in the solid state scatters in the reaction tank and is dissolved after being heated, which causes coloring of the aromatic polycarbonate. On the other hand, too much water is
It is not preferable because it causes hydrolysis of phosgene and industrially reduces productivity. The preferred amount of water used is 0.8 to 2. per mol of the aromatic dihydroxy compound.
It is about 2 liters, and particularly preferably 0.9 to 1.7 liters.

The molecular weight regulator (also referred to as an end capping agent) used in the present invention is for regulating the final molecular weight in the process of producing an aromatic polycarbonate, and generally,
A monovalent hydroxyaromatic compound is used. In addition, a monovalent hydroxyaromatic compound chloroformate compound, a monovalent carboxylic acid group-containing compound, a monovalent carboxylic acid chloride compound, etc. Good. Examples of the monovalent hydroxyaromatic compound include phenol, p-tertiarybutylphenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol and o-quan. Millphenol, m-cumylphenol, p
-Cumylphenol, o-cyclohexylphenol,
m-cyclohexylphenol, p-cyclohexylphenol, o-octylphenol, m-octylphenol, p-octylphenol, o-nonylphenol, m-nonylphenol, p-nonylphenol, o
-Methoxyphenol, m-methoxyphenol, p-
With methoxyphenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-bromophenol, m-bromophenol, p-bromophenol, pentabromophenol, pentachlorophenol, β-naphthol, α-naphthol, etc. is there.

Examples of the monovalent hydroxyaromatic compound chloroformate compound include the above-mentioned monovalent hydroxyaromatic compound chloroformate derivatives, and examples of the compound having a monovalent carboxylic acid group include: Acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid,
Caprylic acid, 2,2-dimethylpropionic acid, 3-methylbutyric acid, 3,3-dimethylbutyric acid, 4-methylvaleric acid,
3,3-dimethylvaleric acid, 4-methylcaproic acid, 2,
4-Dimethylvaleric acid, 3,5-dimethylcaproic acid, fatty acids such as phenoxyacetic acid, p-propoxybenzoic acid, p
-Butoxybenzoic acid, p-pentyloxybenzoic acid, p
-Hexyloxybenzoic acid, p-octyloxybenzoic acid, and other benzoic acids, and examples of the monovalent carboxylic acid chloride compound include chloride derivatives of the above-mentioned compounds having a monovalent carboxylic acid group. These alone
Alternatively, two or more kinds are mixed and used. Phenol or p-tert-butylphenol is preferable because of easy availability.

The amount of the molecular weight modifier used in the method of the present invention is determined according to the final molecular weight of the desired aromatic polycarbonate. When producing several types of products with different molecular weights, select the amount of the molecular weight regulator that corresponds to the production of the product with the highest molecular weight, collect the product with the lower molecular weight from the intermediate polymerization tank, and collect it from the last polymerization tank. Aromatic polycarbonate of molecular weight finally reached is obtained. In order to exhibit various physical properties of the aromatic polycarbonate such as moldability, thermal decomposition resistance, impact resistance, etc., about 12,000-30
The number average molecular weight of 000 is preferable, and the amount of the molecular weight modifier necessary for producing an aromatic polycarbonate having a number average molecular weight in the above range is 2 with respect to the amount of the aromatic dihydroxy compound used. 0.0 to 6.0 mol% is preferable. If the amount of the molecular weight regulator used is less than 2.0 mol% with respect to the amount of the aromatic dihydroxy compound used, the fluidity of the final product at the time of melting is poor and molding is very difficult. Become. When it is more than 6.0 mol%, the resulting aromatic polycarbonate is not preferable because the impact resistance is significantly impaired. The addition of the molecular weight modifier is preferably carried out in advance in the base aqueous solution of the aromatic dihydroxy compound before the reaction, but other methods, for example, in the state of the organic solvent solution or the base aqueous solution, the aromatic dihydroxy compound is added. It is also possible to supply separately from the base aqueous solution.

The polymerization catalyst used in the present invention is a tertiary amine,
Examples thereof include quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, nitrogen-containing heterocyclic compounds and salts thereof, imino ethers and salts thereof, and compounds having an amide group. Preferably, it is a trialkylamine which is a tertiary amine, more preferably on the carbon atom at the 1-position and 2-position such as triethylamine, tri-n-propylamine, diethyl-n-propylamine, tri-n-butylamine and the like. Is a trialkylamine having an alkyl group of C1 to C4 without branching. Triethylamine is particularly preferable in terms of easy availability and excellent catalytic effect.

The amount of the polymerization catalyst used is preferably about 0.0005 to 0.2 mol%, more preferably 0.005 to 0.2 mol%, based on the aromatic dihydroxy compound.
Most preferred is 02 to 0.2 mol%. When the amount of the catalyst is extremely smaller than 0.0005 mol%, the catalytic effect for efficiently forming the aromatic polycarbonate does not appear so much,
An extremely long reaction time is required to reach the final molecular weight. Therefore, it is necessary to increase the number of subsequent tank-type reactors following the first tank-type reactor or the retention time thereof. Even in the case of recovering the intermediate product of the reaction, it takes an unnecessarily long polymerization time to reach the desired molecular weight, which is not preferable. Further, the catalyst amount is 0.
When it is more than 2 mol%, the polymerization rate becomes fast and the final molecular weight is reached in a short polymerization time, so that the range of selection of products in the middle of the reaction is narrowed and it becomes difficult to control,
An aromatic polycarbonate having a large polydispersity index is often obtained, and it is not so preferable from the viewpoint of physical properties (eg, heat resistance) of the aromatic polycarbonate produced. These catalysts are used to produce aromatic polycarbonate oligomers or aromatic polycarbonates, and the amount of the above-mentioned catalyst is added to the amount of the catalyst contained in the organic solvent, reaction water, and washing water recovered when these are recovered. It is preferable to prepare by adding a new catalyst.

It is also within the scope of the present invention to add a branching agent, if desired, to produce a branched aromatic polycarbonate. The branching agent, three or more aromatic hydroxy group, chloroformate group, carboxylic acid group,
Compounds having a carboxylic acid chloride group and an active halogen atom, such as phloroglucinol and 4,6-
Dimethyl-2,4,6-tris (4'-hydroxyphenyl) -2-heptene, 4,6-dimethyl-2,4,6
-Tris (4'-hydroxyphenyl) heptane, 1,
3,5-tris (4'-hydroxyphenyl) benzene, 1,1,1-tris (4'-hydroxyphenyl)
Ethane, tris (4′-hydroxyphenyl) phenylmethane, 2,2-bis [4 ′, 4′-bis (4 ″ -hydroxyphenyl) -cyclohexyl] propane, 2,
4-bis (hydroxyphenylisopropyl) phenol, 2,6-bis (2-hydroxy-5'-methylbenzyl) -4-methylphenol, 2- (4'-hydroxyphenyl) -2- (2 '', 4 '' -Dihydroxyphenyl) -propane, 1,4-bis (4 ', 4''-dihydroxytriphenylmethyl) benzene, trimesic acid trichloride, cyanuric acid chloride, 3,3-
Bis (4'-hydroxyphenyl) -2-oxo-2,
3-dihydroindole, 3,3-bis (4'-hydroxy-3'-methylphenyl) -2-oxo-2,3-
Dihydroindole and the like.

The amount of the branching agent used can be changed according to the degree of branching of the desired aromatic polycarbonate, but usually it is 0.
It is preferable to use about 05 to 2.0 mol%. Further, the branching agent is preferably added in advance in the basic aqueous solution of the aromatic dihydroxy compound before the reaction,
In another method, for example, in the state of an organic solvent solution or an aqueous base solution, it may be added at any time during the reaction, that is, at any time when polymerization is performed.

Carbonyl halide is preferably used as a raw material for forming a carbonate bond in the present invention. For example, phosgene, carbonyl bromide, carbonyl iodide, carbonyl fluoride and the like, and a mixture thereof may be used. Further, it may be a compound having the ability to form a haloformate group, for example, trichloromethylchloroformate which is a dimer of phosgene, bis (trichloromethyl) carbonate which is a trimer of phosgene, and the like. Usually, it is preferable to use phosgene. The amount of the carbonyl halide used in the present invention is about 1.0 to the amount of the aromatic dihydroxy compound.
A 1.3-fold molar amount is preferred. When the amount is extremely less than 1.0 times the molar amount, unreacted aromatic dihydroxy compound remains, which is not preferable. The use of carbonyl halide in excess of 1.3 times the molar amount results in the production of a large amount of oligomers terminated with haloformate groups, and as a result, a large amount of aromatic dihydroxy compound, base, etc. must be newly added. For example, since the ratio of the haloformate end group and the OH group (or phenolate group) of the oligomer in the reaction system becomes excess haloformate end group,
This is not preferable because it results in the formation of an aromatic polycarbonate having a low molecular weight that is terminated by haloformate termination.

The carbonyl halide may be supplied in the form of gas, liquid or solution. It is preferable to supply in a gas state, but it may be supplied in a state of an organic solvent solution dissolved in an organic solvent such as dichloromethane. Further, in order to stably and constantly supply carbonyl halide, it may be preferable that the carbonyl halide supplied to the first tank reactor is in a state of an organic solvent solution. When supplying the carbonyl halide as an organic solvent solution, the carbonyl halide and the organic solvent may be mixed in advance to prepare an organic solvent solution, and the organic solvent solution may be continuously supplied. In front of the above, the carbonyl halide and the organic solvent may be continuously brought into contact with each other using a device such as a pipe or a gas absorption device to continuously prepare an organic solvent solution of the carbonyl halide. After mixing the carbonyl halide and the organic solvent, in the case of producing an aromatic polycarbonate by supplying to the tank reactor, it is necessary that the polymerization catalyst does not exist in the organic solvent, When the organic solvent is separately supplied and when the organic solvent is supplied after the carbonyl halide is brought into contact with the aqueous reaction solution, 0.0005 to 0 to the aromatic dihydroxy compound is added to the organic solvent. A polymerization catalyst may be present within the range of 0.2 mol%.

Any organic solvent may be used as long as it is substantially insoluble in water, inert to the reaction, and capable of dissolving the aromatic polycarbonate. For example, dichloromethane, chloroform, 1,2-
It is preferable to use aliphatic chlorinated compounds such as dichloroethane, 1,2-dichloroethylene, trichloroethane, tetrachloroethane, dichloropropane, or a mixture thereof. Further, an organic solvent in which an aromatic hydrocarbon such as toluene, xylene and ethylbenzene, an aliphatic hydrocarbon such as hexane, heptane and cyclohexane are mixed with chlorinated hydrocarbons and a mixture thereof may be used. Particularly preferred is dichloromethane. Further, in the present invention, it is preferable to use the recovery solvent produced when the aromatic polycarbonate produced by the method of the present invention is recovered, as it is, or as a mixture with a new organic solvent.

The amount of the organic solvent used is preferably determined so that the viscosity of the organic phase during the polymerization reaction does not exceed 300 cp all the time, and is maintained so that the concentration of the aromatic polycarbonate in the organic solvent solution does not fluctuate during the reaction. By satisfying this condition, the steady-state of the reaction can be secured promptly and stably.Therefore, control of the molecular weight of the aromatic polycarbonate in the intermediate polymerization tank by the residence time or continuous removal from the last tank reactor is performed. The molecular weight of the aromatic polycarbonate recovered from the reaction mixture discharged is controlled with good reproducibility throughout. When the viscosity of the organic phase exceeds 300 cp,
Since the stirring efficiency is lowered, the reaction rate becomes slower, and the steady state of the intermediate polymerization tank becomes unstable, so that the molecular weight of the aromatic polycarbonate recovered from the intermediate tank and the final tank varies. Even when the concentration of the aromatic polycarbonate in the organic solvent solution becomes thin or thick, the steady state of the intermediate polymerization tank fluctuates. I have to keep it. The room temperature 300 cp viscosity means that when the number average molecular weight of the target aromatic polycarbonate is 20,000, the concentration of the aromatic polycarbonate in the organic solvent solution at the end of the polymerization is about 15% by weight. When the number average molecular weight of the group polycarbonate is 30,000, the amount of the organic solvent is such that the concentration of the aromatic polycarbonate in the organic solvent solution at the end of the polymerization is about 12% by weight.

The amount of the organic solvent used is affected by the amount of water used in the reaction, but the amount of the organic solvent in the initial stage of the reaction is usually 0.
It is preferably 8 to 1.2: 1. The present inventors have reacted with an aqueous solution of an alkali metal or alkaline earth metal base of an aromatic dihydroxy compound with a carbonyl halide in the presence of a polymerization catalyst to produce an aromatic polycarbonate, and an organic solvent and water. As a result of examining the volume ratio of the phases, it was found that when the volume ratio is within the above range, it is possible to effectively reduce the hydrolysis amount of the carbonyl halide, which has been difficult in the conventional tank reactor. It was Furthermore, it has been found that when the aromatic polycarbonate is produced with a solvent amount ratio limited within the above range, the polymerization is completed very quickly. When the amount of solvent is within the above range, since complete mixing is efficiently performed, it is possible to stably produce an aromatic polycarbonate oligomer and aromatic polycarbonate, and when the amount of solvent is outside the above range, In comparison, uniform emulsification is possible with less stirring power. When the organic solvent is less than the above range, a large amount of stirring power is required to form a uniform emulsified state, and when the amount of the organic solvent is more than the above range, a larger stirring power is required. Since it is necessary, it is not preferable in terms of production cost.

In the method of the present invention, about 10 to 50 ° C.
Reaction temperatures of are used. If the reaction temperature is lower than 10 ° C, the reaction rate becomes too slow, which is not practical.
Further, at a reaction temperature higher than 50 ° C., the solubility of the carbonyl halide in an organic solvent is lowered, so that preferable reaction efficiency may not be obtained, and the carbonyl halide and / or the haloformate compound derived therefrom may not be hydrolyzed. The decomposition reaction is also accelerated, which is not preferable. When the organic solvent used is dichloromethane, it can be carried out at a reflux temperature of about 39 ° C. under atmospheric pressure. The reaction pressure is usually atmospheric pressure, but if desired, pressure conditions below atmospheric pressure and above atmospheric pressure are also used.

In the present invention, at least three tank reactors connected in series are used to carry out the reaction continuously. In the first step of the embodiment of the present invention, a mixture of an aromatic dihydroxy compound, a base, a polymerization catalyst, a molecular weight modifier, water, and optionally a branching agent and an antioxidant is prepared. At this time, the temperature at which the aromatic dihydroxy compound is dissolved is preferably 20 ° C. or lower in order to prevent coloration during the dissolution of the aromatic dihydroxy compound. Also,
This preparation may be carried out batchwise at any time, but preferably it is prepared continuously and the prepared mixture is used continuously. The water used at this time is reaction water containing a small amount of the polymerization catalyst used when producing the aromatic polycarbonate, or washing water, and the inorganic salt in the water is appropriately adjusted to 0.3 to 20% by weight. Water that has been concentrated and diluted can be used.

Next, this mixture, the carbonyl halide and the organic solvent are supplied to the first tank reactor. As this supply method, a method of supplying or dropping below the liquid surface or above the liquid surface by an arbitrary separate pipe may be adopted, and the carbonyl halide and the organic solvent may be optionally mixed and then supplied. May be. As for the ratio of each supply amount, each supply amount per unit time is preferably within the range of the above-mentioned usage amount. That is, the carbonyl halide is about 1.0 to 1.3 times mol per unit time with respect to the aromatic dihydroxy compound, and the amount of the organic solvent is about 0.8 by volume ratio with respect to water in the aqueous base solution. It is preferable to supply it so that it is about 1.2: 1.

The stirring during the reaction may use any stirring device and stirring conditions, but extremely fast stirring accelerates the hydrolysis of the carbonyl halide or the haloformate group derived therefrom. Therefore, it is not preferable, and if the stirring speed is extremely slow, the contact area at the interface decreases, and the reaction under the interface conditions does not proceed well, which is not preferable. The preferable stirring speed cannot be shown only by the number of revolutions because it depends on the shape of the polymerization tank in which the reaction is carried out, the shape of the stirring blade, etc., but usually, the organic solvent phase and the aqueous phase are almost uniformly mixed. The stirring speed.

In the present invention, the residence time of the reaction mixture in the first tank reactor is preferably adjusted to be between 1 and 45 minutes. The retention time can be shortened by increasing the feed rate, but when the retention time is shortened, the amount of heat generated in the first tank reactor increases. Therefore, if the reaction is carried out for a residence time shorter than 1 minute, heat is generated which is difficult to control. Further, the reaction with a residence time excessively longer than 45 minutes is not preferable because the first tank reactor is required to be large-scaled and an expensive apparatus is required, and the molecular weight of the aromatic polycarbonate produced is also not preferable. It is not preferable because the distribution may spread. From an organic solvent solution containing the aromatic polycarbonate oligomer extracted from the first tank reactor and an aqueous phase containing 4 to 30 mol% of unreacted aromatic dihydroxy compound with respect to the charged aromatic dihydroxy compound. The resulting heterogeneous mixture is further fed to at least two tank reactors connected in series to carry out a polymerization reaction. The residence time after the second tank depends on the relationship between the target molecular weight and conditions such as the amount of catalyst, but it is about 1 to 70 minutes, preferably 10 to 6 minutes.
It is preferably in the range of 0 minutes. 1 in the middle polymerization tank
When the residence time is shorter than the minute, the increase in the molecular weight of the product before and after the polymerization tank is extremely small, and the effect of making different products is not exhibited, which is not preferable. Also, a residence time that is excessively longer than 70 minutes is not preferable because an irrational reaction condition of slowing down the polymerization rate is forced.

In the present invention, the retention components are continuously recovered from two or more arbitrary tanks including the final tank while keeping the retention time in each tank constant. Therefore,
The reaction mixture that is withdrawn from the polymerization reaction tank after a predetermined residence time is further divided into one that is supplied to the next polymerization reaction tank and one that is stopped and recovered if desired. In this manner, the reaction mixture continuously supplied to at least three tank-type reactors connected in series has two or more reaction tanks including the final tank while keeping the residence time in each reaction tank constant. It is continuously collected from any tank.

In the present invention, the number of tank-type reactors connected in series and the optional tank for recovering the retained components can be appropriately determined depending on the desired kind of aromatic polycarbonate and the like, but at least 3 tanks or more. Is required, and preferably 3 to 5 tanks. Further, the molecular weight of the aromatic polycarbonate recovered from the intermediate polymerization tank, the molecular weight of the aromatic polycarbonate oligomer supplied, the catalyst amount,
And it can be changed by the polymerization time, that is, the residence time in the polymerization reaction tank.

In the present invention, the reaction mixture consisting of the organic phase in which the aromatic polycarbonate is dissolved and the aqueous phase is continuously withdrawn from the tank reactor, but this withdrawal method can be selected arbitrarily. . For example, overflow, withdrawal with a pump, or withdrawal from the bottom or side of the reaction tank with a pump, return to another position in the reaction tank, and circulate, while supplying the same amount to the reaction tank at any position of the pipe. A quantity of the reaction mixture may be withdrawn. In addition, the extraction position is provided at the bottom of the tank-type reactor, and the reaction mixture is extracted quasi-continuously, that is, intermittently at extremely short intervals, or the reaction mixture is controlled while controlling the flow rate with the control valve. It also includes continuous withdrawal from the bottom or intermediate position of the.

The organic solvent solution of the aromatic polycarbonate recovered from the intermediate polymerization tank is separated from the aqueous phase and then mixed with an aqueous solution of an alkali metal or alkaline earth metal base as a molecular weight regulator and stirred to haloformate at the end. It is preferable to perform a treatment for sealing the group. The organic solvent solution of the aromatic polycarbonate in any tank thus produced is
After neutralization with acid, washing with water is repeated until the electrolyte is substantially absent. Then, the organic solvent can be removed from the solution of the aromatic polycarbonate in an organic solvent by a known method to obtain an aromatic polycarbonate.

Further, in the method for producing a polycarbonate of the present invention, for the purpose of imparting thermal stability, light resistance, weather resistance, flame retardancy, and other properties during the processing of an aromatic polycarbonate at any time during the reaction. It is possible to add known additives for aromatic polycarbonate. Known additives include processing and heat stabilizers, antioxidants, ultraviolet absorbers, mold release agents, organic halogen compounds, alkali metal sulfonates, glass fibers, glass beads, barium sulfate and TiO2.

[0046]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. The analytical methods used in the examples are shown below. * Molecular weight measurement: The number average molecular weight and the weight average molecular weight in terms of polystyrene were measured by GPC (gel permeation chromatography). * End group of aromatic polycarbonate: Chloroformate end group was quantified by silver chloride titration, and OH end group was titrated by bromination method.

Example 1 8406 g (36.87 mol) of bisphenol A and p-tert-butylphenol 1 as a molecular weight regulator
74.759 g (1.165 mol), triethylamine 5.994 g (0.05935 mol), caustic soda 42
77 g (106.93 mol) and 16.794 g of sodium hydrosulfite were dissolved in 57.06 kg of water to prepare an aqueous mixture having a total weight of 69.94 kg. 129.56 g each of this mixture, phosgene, and an organic solvent
/ Min, 7.638 g (0.07715 mol) / min, 12
It was introduced into the first tank reactor at 7.37 g / min. The tank reactor is provided with an outlet for overflow, from which the reaction mixture is discharged at 264.57 g / min. The residence time was about 20 minutes. Regarding the molecular weight of the aromatic polycarbonate oligomer in the discharged reaction mixture, the number average molecular weight was 3000 to 3300, the weight average molecular weight was 9800 to 10600, and the unreacted monomer was 6.3 to 6.5 mol%.

The continuously discharged reaction mixture was continuously supplied to the second tank reactor by using a pipe. Polymerization was carried out in the second reactor for a residence time of 30 minutes, and the continuously discharged reaction mixture was continuously changed over by a revolver system to change the flow path to 176.38 in the third tank reactor.
Supply at g / min, 88.19 g / in the storage tank for intermediate product recovery
Sorted to supply in minutes. The recovered reaction mixture was immediately separated by separating the aqueous phase, mixed with a caustic soda aqueous solution of p-tertiarybutylphenol, subjected to end-capping treatment, separated again, and the organic phase was mixed with hydrochloric acid for neutralization. The reaction mixture supplied to the third tank reactor was further polymerized with a residence time of 30 minutes. The reaction mixture continuously discharged from the third tank type reactor was continuously supplied to the fourth tank type reactor at 88.19 g / min by switching the flow path continuously, and 88.19 to the storage tank for recovering the intermediate product. It was fractionated so that it was fed at 19 g / min. In the same manner as above, the recovered reaction mixture was immediately separated by removing the aqueous phase, mixed with an aqueous caustic soda solution of p-tert-butylphenol, subjected to end-capping treatment, and again separated, and the organic phase was mixed with hydrochloric acid. I made it The reaction mixture supplied to the fourth tank reactor was further polymerized with a residence time of 60 minutes. The reaction mixture continuously discharged from the fourth tank reactor was immediately separated into liquids and neutralized with hydrochloric acid. The organic phase collected in each tank was washed with pure water until the electrolyte was exhausted. The organic solvent was evaporated from the organic solvent solution containing this aromatic polycarbonate to obtain a solid aromatic polycarbonate.

This continuous operation was carried out for 9 hours, and the molecular weight of the aromatic polycarbonate and the unreacted end groups were analyzed every hour. The aromatic polycarbonate recovered from each tank had a number average molecular weight in the second tank, respectively. 12300 ~
12,500, weight average molecular weight 32,000 to 3250
0, unreacted end group is chloroformate end group 10pp
m or less, OH end group is 0.0015 to 0.0016Br
g / g, and the third tank has a number average molecular weight of 19100 to
19300, weight average molecular weight of 49000-4950
0, unreacted end group is chloroformate end group 10pp
m or less, OH end group is 0.0015 to 0.0016Br
g / g, and in the fourth tank, the number average molecular weight is 207.
00-20900, weight average molecular weight 51500-52
000, the unreacted end group has a chloroformate end group of 10
ppm or less, OH end group is 0.0013 to 0.0014
It was Brg / g. The aromatic polycarbonate obtained from the fourth tank reached the final molecular weight, and no further increase in the molecular weight was observed. As described above, the aromatic polycarbonate recovered from each tank showed a stable molecular weight, and three products having different molecular weights could be simultaneously produced on the same production line.

Example 2 Example 2 was repeated except that 120.562 g (0.804 mol) of p-tertiarybutylphenol as a molecular weight modifier was used instead of 174.759 g (1.165 mol). The operation was performed in the same manner as in 1. The residence time in the first tank-type reactor was 20 minutes, and the molecular weight of the obtained aromatic polycarbonate oligomer was analyzed every one hour. As a result, the number average molecular weight was 3500 to 370.
0, the weight average molecular weight is 11800 to 12300,
The amount of unreacted monomer was 6.7 to 7.4 mol%.
The reaction mixture continuously discharged from the first tank reactor at 264.57 g / min was continuously supplied to the second tank reactor through a pipe. Residence time 30 in second reactor
Polymerization in minutes, the reaction mixture discharged continuously is supplied to the third tank type reactor at 176.38 g / minute by continuously switching the flow path by the revolver system, and used as a storage tank for intermediate product recovery. It fractionated so that it might be supplied at 88.19 g / min. Thereafter, polymerization was carried out in the third tank reactor for a residence time of 30 minutes and in the fourth tank reactor for a residence time of 60 minutes, and the reaction mixture was recovered from each tank at 88.19 g / min. The recovered reaction mixture was subjected to the same post-treatment as in Example 1, and the organic solvent was distilled off from the organic solvent solution containing the aromatic polycarbonate to obtain a solid aromatic polycarbonate.

This continuous operation was carried out for 9 hours, and the molecular weight of the aromatic polycarbonate and the unreacted end groups were analyzed hourly. The aromatic polycarbonate recovered from each tank was found to have a number average molecular weight in the second tank. 16000 ~
16200, weight average molecular weight 44,800-4,530
0, unreacted end group is chloroformate end group 10pp
m or less, OH end group is 0.0017 to 0.0018Br
g / g, and the third tank has a number average molecular weight of 24,800-
25,000, weight average molecular weight of 65,000 to 6550
0, unreacted end group is chloroformate end group 10pp
m or less, OH terminal group is 0.0013 to 0.0014Br
g / g, and in the fourth tank, the number average molecular weight is 278.
00-28,000, weight average molecular weight 69500-70
000, the unreacted end group has a chloroformate end group of 10
ppm or less, OH end group is 0.0013 to 0.0014
It was Brg / g. The aromatic polycarbonate obtained from the fourth tank reached the final molecular weight, and no further increase in the molecular weight was observed. As described above, the aromatic polycarbonate recovered from each tank showed a stable molecular weight, and it was shown that the method of the present invention can be carried out by changing the target depending on the amount of the molecular weight modifier.

Example 3 In the same manner as in Example 1, except that the residence time of the second and third tank reactors was 30 minutes in Example 1, but the residence time was 20 minutes. To produce an aromatic polycarbonate. The aromatic polycarbonate recovered from each tank had a number average molecular weight of 10300 in the second tank.
-10500, weight average molecular weight 29500-2970
0, unreacted end group is chloroformate end group 10pp
m or less, OH terminal group is 0.0016 to 0.0017 Br
g / g, and the third tank has a number average molecular weight of 17,500-
17700, weight average molecular weight 45200 to 4570
0, unreacted end group is chloroformate end group 10pp
m or less, OH end group is 0.0015 to 0.0016Br
g / g, and in the fourth tank, the number average molecular weight is 207.
00-20900, weight average molecular weight 51500-52
000, the unreacted end group has a chloroformate end group of 10 ppm or less, and an OH end group of 0.0013 to 0.0.
It was 014 Brg / g. The aromatic polycarbonate obtained from the fourth tank has reached the final molecular weight,
No further increase in molecular weight was observed. Like this
It was shown that the molecular weight in the steady state of each tank can be changed by the residence time of the polymerization reaction tank.

Comparative Example 1 In Example 1, the residence time of the first tank reactor was set to 2
An aromatic polycarbonate was produced in the same manner as in Example 1 except that the reaction tank was set to have a capacity of 0 minutes and the residence time was changed to 60 minutes. When the molecular weight of the obtained aromatic polycarbonate oligomer was analyzed every hour, the number average molecular weight was 11,200 to 11,500,
The weight average molecular weight was 37,500-38,000, and the unreacted monomer was 3.0-3.2 mol%. The aromatic polycarbonate recovered from each tank has a number average molecular weight of 12000 to 12200 and a weight average molecular weight of 42800 to 43300 in the second tank, respectively.
The unreacted end group has a chloroformate end group of 10 pp.
m or less, OH terminal group is 0.0018 to 0.0019Br
g / g, number average molecular weight is 12600 in the third tank
-12,800 and a weight average molecular weight of 44,900-4
5400, the unreacted end group has a chloroformate end group of 10 ppm or less and an OH end group of 0.0018 to 0.0
019 Brg / g, and the fourth tank has a number average molecular weight of 12,800 to 13,000 and a weight average molecular weight of 454.
00-45900, the unreacted end groups have a chloroformate end group of 10 ppm or less and an OH end group of 0.0016.
It was -0.0017 Brg / g. As described above, when the residence time in the first tank reactor is long and is out of the range defined by the present invention, the desired molecular weight is not reached even in the end, and the molecular weight distribution tends to widen. Not to mention making differently,
It is not possible to obtain the desired aromatic polycarbonate.

[0054]

Industrial Applicability According to the present invention, several kinds of aromatic polycarbonates having different molecular weights, different processability and different mechanical properties can be efficiently produced simultaneously in a single production line.

Front page continued (72) Inventor Masahiro Ota 30 Asamu-cho, Omuta-shi, Fukuoka Mitsui Toatsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. An aromatic polycarbonate is obtained by reacting an aqueous alkali metal or alkaline earth metal base solution of at least one aromatic dihydroxy compound with a carbonyl halide compound in the presence of a polymerization catalyst, a molecular weight modifier and an organic solvent. In the production, the above substances are continuously supplied to at least three tank-type reactors connected in series to carry out the reaction, and while the residence time in each tank is kept constant, two tanks including a final tank are used. A method for producing an aromatic polycarbonate, characterized in that a retention component is continuously recovered from the above arbitrary tank. 2. The residence time in the first tank reactor is in the range of 1 to 45 minutes, and the residence time in each tank after the second tank is in the range of 1 to 70 minutes. the method of.