ES2367728T3 - PROCEDURE FOR MANUFACTURING POLYCARBONATES. - Google Patents

Abstract

Process for continuously manufacturing polycarbonates or copolycarbonates or diaryl carbonates according to the interphase procedure from at least one diphenol or monophenol, phosgene and at least one catalyst if necessary in the presence of at least one chain switch and / or branching, characterized because (a) a mixture of the organic and aqueous phases is continuously generated, the organic phase containing at least one solvent suitable for the polycarbonate or diaryl carbonate and totally or partially the phosgene and the aqueous phase containing the diphenol or the aqueous phase (s) or monophenol (s), water and alkaline hydroxide solution, (b) a reaction of the diphenol (s) or monophenol (s) and phosgene is carried out to give oligocarbonates or to give aryl esters of chloroformic acid or diaryl carbonates or a mixture of aryl esters of chloroformic acid and diaryl carbonates, (c) the oligocarbonates or aryl esters of the acid cl are reacted oroformic and / or diaryl carbonates then in at least one reactor with the addition of additional alkali hydroxide solution, optionally chain switch (s) and eventually at least one other catalyst, characterized in that the continuous mixing of the organic and aqueous phases in (a) and the reaction to give oligocarbonates or aryl esters of chloroformic acid and / or diaryl carbonates in (b) are carried out in one or several pump (s), which - works (works) according to the stator-rotor principle - it can (can) be thermostatted and - it presents (presents) at least respectively one input for the organic phase and the aqueous phase and possibly other inputs for the catalyst, chain switch, branching and / or additionally the alkali hydroxide solution as well as at least an outlet for the mixture containing oligocarbonates or of aryl esters of the chloroformic acid-diaryl carbonates.

Description

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The object of the present invention is a process for continuously manufacturing polycarbonates and diaryl carbonates according to the procedure of the interface procedure in which both the mixing of the organic and aqueous phase and the previous oligomerization stage or the ester formation of the chloroformic acid of the monoaryl compound in a special pump.

The manufacture of polycarbonates according to the interface procedure has already been described by Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, volume 9, Interscience Publishers, New York, London, Sydney 1964, p. 33-70; D.C. Prevorsek, B.T. Debona and Y. Kesten, Corporate Research Center, Allied Chemical Corporation, Morristown, New Jersey 07960: "Synthesis of Poly (ester Carbonate) Copolymers" in Journal of Polymer Science, Polymer Chemistry Edition, vol. 18, (1980) ”; P. 75-90, D. Freitag, U. Grigo, P.R. Müller, N. Nouvertne ’, BAYER AG,“ Polycarbonates ”in Encyclopedia of Polymer Science and Engineering, volume 11, Second Edition, 1988, S. 651-692 and schließlich von Dres. U. Grigo, K. Kircher and P. R-Müller "Polycarbonate" in Becker / Braun, Kunststoff-Handbuch, volume 3/1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag München, Wien 1992, p. 118-145.

In addition, EP-A 0 517 044 or EP-A 520 272 also describes the interface procedure for manufacturing polycarbonate:

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To manufacture polycarbonate according to the interphase process, the phosgenation of a disodium salt of a bisphenol disposed in aqueous-alkaline solution or suspension or of a mixture of different bisphenols in the presence of an inert organic solvent or solvent mixture, which forms together to the aqueous phase a second organic phase. The produced oligocarbonates, which are mainly found in the organic phase, are condensed with the help of suitable catalysts to give high molecular weight polycarbonates, dissolved in the organic phase, and the molecular weight can be controlled by suitable chain switches (monofunctional phenols). The organic phase is finally separated and the polycarbonate is isolated therefrom by various processing steps.

The synthesis of polycarbonates as well as the synthesis of diaryl carbonates can be carried out continuously or discontinuously. Therefore, the reaction can be carried out in stirring vessels, tubular reactors, pump transfer reactors or cascades of stirring vessels or their combinations, guaranteeing by using the aforementioned mixing elements that the aqueous and organic phase may not possibly separate until The synthesis mixture has reacted, that is, it no longer contains any phosgene chlorine or esters of saponifiable chlorocarboxylic acids.

The first stage to form the oligocarbonates is carried out according to the state of the art for example in a pump transfer reactor; see for example EP 1 249 463 A1, US 2004/0158026 A1, US 6,613,868 B2. The mixture of the phosgene introduced with the sodium salt of an equally introduced bisphenol (or a mixture of different bisphenols) as well as the first stages of oligomerization are carried out in the pump transfer reactor. In this regard, the chloroformate groups produced react with existing phenolate groups to give increasing oligomers, which contain different terminal groups (phenolate or chloroformate or of both mixed species). A certain percentage of bisphenol introduced is still unreacted in the mixture. Specifically, the pump transfer reactor has advantages so that they cannot undergo dosage or concentration fluctuations without damping up to the final product, but rather a balance of fluctuations is achieved by remixing with pump transfer rate adjusted for the input. or exit of the reaction mixture. However, a significant drawback is that relatively large molecular weight distributions occur for large-scale advantageous parameter adjustments. An additional drawback can be seen in that the pump transfer reactors represent relatively bulky elements.

The manufacture of diaryl carbonates (such as diphenyl carbonate) is usually carried out by a continuous process, by the manufacture of phosgene and then the reaction of monophenols and phosgene in an inert solvent in the presence of base and a nitrogen catalyst in the boundary surface

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The manufacture of diaryl carbonates, for example, by the interface procedure is described in principle in the literature, see for example in Chemistry and Physics of Polycarbonates, Polymer Reviews, H. Schnell, vol. 9, John Wiley and Sons, Inc. (1964), p. 50/51.

In the patent application US-A-4 016 190 a method of producing diaryl carbonates is described, which is carried out at temperatures above 65 ° C. The pH value is adjusted in this procedure first in a low way (pH = 8 to 9) and then in a high way (pH = 10 to 11).

In document EP1219589 A1, EP1216981 A2, EP1216982 A2 and EP784048 A1 process optimizations are described by improving mixing and maintaining a temperature and pH profile as well as product isolation.

To produce diaryl carbonate according to the interphase procedure, the phosgenation of a sodium salt of a monophenol or a mixture of different monophenols arranged in aqueous-alkaline solution or suspension in the presence of an inert organic solvent or solvent mixtures is carried out, which forms a second organic phase next to the aqueous phase. The aryl esters of the chloroformic acid produced, which are found mainly in the organic phase, are reacted with the aid of suitable catalysts to give diaryl carbonates dissolved in the organic phase. The organic phase is finally separated and the diaryl carbonate is isolated therefrom by various reprocessing steps.

The first step to form the aryl esters of chloroformic acid and / or diaryl carbonates is carried out according to the state of the art for example in a pump transfer reactor; see for example EP 1 249 463 A1, US 2004/0158026 A1, US 6,613,868 B2. In this pump transfer reactor, in this respect, the mixture of the phosgene introduced with the sodium salt of a monophenol (or a mixture of different monophenols) is also introduced to give aryl esters of chloroformic acid and / or carbonates of diaryl A certain percentage of the introduced monophenol is still unreacted in the mixture. Specifically, the pump transfer reactor has advantages so that they cannot undergo dosage or concentration fluctuations without damping up to the final product, but rather a balance of fluctuations is achieved by remixing with pump transfer rate adjusted for the input. or exit of the reaction mixture. However, a significant drawback is that for large-scale advantageous parameter adjustments, percentages are present which have not yet completely reacted from the chloroformic aryl ester in the product composition. Another drawback can be seen in that the pump transfer reactors represent relatively bulky elements.

In these known processes, however, a high value of residual phenol in wastewater from these processes causes considerable disadvantages. Phenols can harm the environment and sewage plants find themselves before a major wastewater problem, which makes it necessary to carry out expensive purification operations.

Thus, WO 03/070639 A1 describes a removal of organic impurities in wastewater by extraction with methylene chloride.

The solution containing sodium chloride is usually released from solvents and organic residues and then they have to be removed.

However, it is also known that the purification of wastewater containing sodium chloride according to EP 1200359 B1 (WO2000078682 A1) or US-A-6340736 can be carried out by ozonolysis and is then suitable for use in the electrolysis of chloride of sodium. It is disadvantageous of ozonolysis that this procedure is very expensive.

Therefore, there is a need for a continuous interphase process for manufacturing polycarbonate or diaryl carbonate, with which the damage of the wastewater resulting from this process with diphenol or monophenol can be further reduced. In this regard, it would also be desirable that polycarbonates with a narrow molecular weight distribution be obtained with such a process without, for example, being able to undergo concentration fluctuations without damping up to the final product (no piston flow behavior). Also in the manufacture of diaryl carbonates, this process prevents concentration fluctuations without extensively damping the aryl esters of the chloroformic acid to the final product.

It was surprisingly found that a significant reduction in the diphenol or monophenol load of the wastewater can be achieved when the mixing of the organic and aqueous phase as well as the previous oligomerization stage is carried out in the interphase process for manufacturing polycarbonates or diaryl carbonates. or the formation of previous chloroformic acid in a special pump. Advantageously also in this process they do not go through concentration fluctuations without damping up to the final product, so that the process according to the invention retains the advantages of the known process according to the state of the art, however it eliminates its drawbacks. A high load of diphenol and / or monophenol of wastewater requires, in a known way, an increase in the addition of phosgene and alkali hydroxide solution to complete the reaction of diphenol or monophenol. Due to the clearly reduced diphenol and / or monophenol loading of the wastewater according to the process according to the invention, such an increase in the addition of phosgene and alkali hydroxide solution can also be avoided. This is advantageous among other things from an economic aspect. In addition, the amount of aryl esters of the chloroformic acid is reduced by the most effective reaction in the case of the manufacture of polycarbonates and diaryl carbonates, which makes a lower amount of amine catalyst necessary and therefore leads to a reduction of the secondary products of urethane.

Therefore, it is the object of the present invention a process for continuously manufacturing polycarbonates or copolycarbonates or diaryl carbonates according to the interphase process from at least one diphenol or monophenol, phosgene and at least one catalyst possibly in the presence of at least one chain switch and / or branching, characterized in that

(to)

a mixture of the organic and aqueous phases is continuously generated, the organic phase containing at least one solvent suitable for the polycarbonate or diaryl carbonate and totally or partially the phosgene and the aqueous phase containing the diphenol (s) or monophenol (s), water and alkali hydroxide solution,

(b)

a reaction of the diphenol (s) or monophenol (s) and phosgene is carried out to give oligocarbonates or to give aryl esters of chloroformic acid or diaryl carbonates or a mixture of aryl esters of chloroformic acid and diaryl carbonates,

(C)

the oligocarbonates or aryl esters of the chloroformic acid and / or diaryl carbonates are then reacted in at least one reactor with the addition of additional alkaline hydroxide solution, optionally chain switch (s) and possibly at least one other catalyst,

characterized in that the continuous mixing of the organic and aqueous phases in (a) and the reaction to give oligocarbonates or aryl esters of the chloroformic acid and / or diaryl carbonates in (b) are carried out in one or several pump (s), which

- works (works) according to the stator-rotor principle

-can (can) be thermostated and

-presents (presents) at least respectively one input for the organic and aqueous phase and possibly other inputs for the catalyst, chain switch, branching and / or additionally alkaline hydroxide solution as well as at least one outlet for the mixture containing oligocarbonates or of aryl esters of diaryl chloroformic acid-carbonate.

In the process according to the invention for manufacturing polycarbonate or diaryl carbonate, at least a part of the solution containing alkaline chloride which is produced in this respect can be returned in an electrolysis of alkali chloride subsequently connected.

The pump (s) used according to the invention is preferably constructed according to the principle of one or more chambers.

The organic phase may already contain all or part of the necessary phosgene before mixing with the aqueous phase. Preferably, the organic phase contains before mixing and all the necessary phosgene including the excess phosgene used.

The entry of phosgene into the organic phase in the manufacture of polycarbonate can be carried out in the form of a gas or in a liquid manner. The excess phosgene used, with respect to the sum of the diphenols used, is preferably between 3% and 100% in mol, especially preferably between 5% and 50% in mol.

The entry of phosgene into the organic phase in the manufacture of diaryl carbonate can be carried out as a gas

or in a liquid way. The excess phosgene used, with respect to the sum of monophenols used, is preferably between 1% and 100% in mol, especially preferably between 2% and 50% in mol.

The pH value of the aqueous phase should be maintained in the alkaline range preferably between 8.5 and 12 by optionally a single subsequent dosage or several subsequent dosages of alkaline hydroxide solution during and after phosgene dosing, while this should be found after the addition of the catalyst to 10 to 14.

Phosgene dosing is carried out before mixing with the aqueous phase totally or partially directly in the organic phase. Possible partial amounts of phosgene can also be dosed before mixing with the aqueous phase in the aqueous phase or after mixing with the aqueous phase in the resulting emulsion. In addition, the phosgene can be fully or partially dosed in a recirculated partial flow of the synthesis mixture of both phases, this partial flow being recirculated preferably before the catalyst addition. Particularly preferred is the complete phosgene dosage before mixing with the aqueous phase directly in the organic phase. In all these embodiments, the pH value ranges described above can be considered and eventually maintained by a single subsequent dosage or several subsequent dosages of sodium hydroxide solution or alkaline hydroxide solution or corresponding subsequent dosage of diphenol solution (ato) or monophenol solution (ato). In the same way, the temperature range must be maintained eventually by cooling or dilution.

The synthesis of polycarbonates from dihydroxydiarylalkanes (diphenols) or diaryl carbonates from monophenols and phosgene in alkaline medium is an exothermic reaction and is carried out in a temperature range of -5 ° C to 100 ° C, preferably 15 ° C to 80 ° C, very especially preferably from 25 ° C to 65 ° C.

Therefore it is necessary that the pump (s) used according to the invention for the mixing and the stage of previous oligomerization or formation of aryl esters of the chloroformic acid can (can) be thermostated at a temperature of 5 ° C to 100 ° C, preferably from 15 ° C to 80 ° C, especially preferably from 25 ° C to 65 ° C.

Depending on each solvent or solvent mixture, it can be operated under normal pressure or overpressure. The pump (s) used according to the invention can be designed for system pressures up to 35 mPa and 450 ° C. Therefore they are suitable for use in a large procedure window.

In the case of the interphase procedure, work is preferably carried out at pressure ranges of 0.1 mPa to 5 mPa, especially preferably at intervals of 0.1 mPa to 1 mPa.

The organic phase may contain a solvent or mixtures of various solvents. Certain suitable solvents are aromatic and / or aliphatic chlorinated hydrocarbons, preferably dichloromethane, trichlorethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane and chlorobenzene and mixtures thereof. However, aromatic hydrocarbons such as benzene, toluene, m- / p- / o-xylene or aromatic ethers such as anisole alone, in admixture or additionally or in admixture with chlorinated hydrocarbons, dichloromethane and chlorobenzene and mixtures thereof may also be used. Another embodiment of the synthesis uses solvents that do not dissolve polycarbonate but only swell it. Therefore, non-solvents for polycarbonate can also be used in combination with solvents, then soluble solvents such as tetrahydrofuran, 1,3- or 1,4-dioxane or 1,3-dioxolane can also be used as solvent in the aqueous phase when the solvent component It forms the second organic phase.

Suitable diphenols are those of the general formula,

HO-Z-OH

wherein Z is a divalent organic moiety with 6 to 30 carbon atoms, which contains one or more aromatic groups. Certain examples of such compounds, which can be used in the process according to the invention, are dihydroxydiarylalkanes such as hydroquinone, resorcinol, dihydroxydiphenyl, bis- (hydroxyphenyl) -alkanes, bis (hydroxyphenyl) cycloalkanes, bis- (hydroxyphenyl) sulfides, bis- ( hydroxyphenyl) -ethers, bis- (hydroxyphenyl) -ketones, bis- (hydroxyphenyl) sulfones, bis- (hydroxyphenyl) -sulfoxides, α, α'-bis- (hydroxyphenyl) -diisopropylbenzenes, bis- (hydroxyphenyl) phthalimidines as well as their alkylated, corealkylated and corehalogenated compounds.

Preferred diphenols are 4,4'-dihydroxy diphenyl, 2,2-bis- (4-hydroxyphenyl) -1-phenyl propane, 1,1-bis- (4-hydroxyphenyl) phenylethane, 2,2-bis- (4- hydroxyphenyl) propane (bisphenol A (BPA)), 2,4-bis- (4-hydroxyphenyl) -2-methylbutane, 1,3-bis- [2- (4-hydroxyphenyl) -2-propyl] benzene (bisphenol M), 2,2-bis- (3-methyl-4-hydroxyphenyl) -propane, bis- (3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis- (3,5-dimethyl-4-hydroxyphenyl) -propane, bis- (3,5-dimethyl-4-hydroxyphenyl) -sulfone, 2,4-bis- (3,5-dimethyl-4-hydroxyphenyl) -2-methylbutane, 1,3-bis- [2- (3 , 5-dimethyl-4-hydroxyphenyl) -2-propyl] -benzene, 1,1-bis- (4-hydroxyphenyl)

cyclohexane,

2-hydrocarbyl-3,3-bis (4-hydroxyaryl) phthalimidines, 3,3-bis (4-hydroxyaryl) -1-aryl-1H-indole-2-one, 2,2-bis- (4

hydroxyaryl) -1-aryl-1H-indole-2-one and 1,1-bis- (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (bisphenol TMC).

Diphenols

especially preferred They are 4,4’-dihydroxydiphenyl, 1,1-bis- (4-hydroxyphenyl) -phenylethane, 2,2-bis- (4

hydroxyphenyl) -propane (bisphenol A (BPA)), 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) -propane, 1,1-bis- (4-hydroxyphenyl) cyclohexane, 2-hydrocarbyl-3, 3-bis (4-hydroxyphenyl) phthalimidine, 3,3-bis (4-hydroxyphenyl) -1-phenyl-1H-indole-2-one, 2,2-bis (4-hydroxyphenyl) -1-phenyl-1H-indole- 2-one, 3,3-bis (4-hydroxyphenyl) -1-methyl-1H-indole-2-one, 2,2-bis (4-hydroxyphenyl) -1-methyl-1Hindole-2-one, 3, 3-bis (4-hydroxyphenyl) -N-methyl-phthalimidine, 3,3-bis (4-hydroxyphenyl) -N-phenyl-phthalimidine and 1,1-bis- (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane ( bisphenol TMC).

These and other suitable diphenols are described for example in documents US-A 2 999 835, US-A 3,148,172 US-A 2,991,273, US-A 3 271 367, US-A 4,982,014 and US-A 2,999 .846, in German patent applications DE-A 1 570 703, DE-A 2 063 050, DE-A 2 036 052, DE-A 2 211 956 and DE-A 3 832 396, the French patent document

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FR-A 1 561 518, in the monograph by H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964, p. 28 and following; P. 102 et seq. And by D.G. Legrand, J.T. Bendler, Handbook of Polycarbonate Science and Technology, Marcel Dekker New York 2000, p. 72 et seq.

In the case of manufacturing according to the invention of homopolycarbonates only one diphenol is used, in the case of manufacturing according to the invention of copolycarbonates several diphenols are used, the used diphenols being logically contaminated, as well as all other chemical compounds and substances auxiliaries added to the synthesis with impurities that originate from their own synthesis, handling and storage, although it is desirable to work with raw materials as clean as possible.

Monophenols especially suitable for use in the new procedure are phenols of formula (I)

image 1

in which

R is hydrogen, halogen or an alkoxycarbonyl moiety or C1 to C9 alkyl branched or unbranched moiety.

Phenol, alkylphenols such as cresols, p-tert-butylphenol, p-cumylphenol, pn-octylphenol, p-iso-octylphenol, pn-nonylphenol and p-iso-nonylphenol, halogenophenols such as p-chlorophenol, 2,4 are also preferred. -dichlorophenol, p-bromophenol and 2,4,6-tribromophenol or salicylic acid methyl ester. Phenol is especially preferred.

By "alkali hydroxide solution" is meant in the context of the invention preferably sodium hydroxide solution, potassium hydroxide solution or mixtures thereof, particularly preferably sodium hydroxide solution.

In the manufacture of diaryl carbonates, the base used for the formation of the phenolate can be an alkali hydroxide solution with hydroxides of the series: Na, K, Li hydroxide. Sodium hydroxide solution is preferred, and is preferably used as a 10% to 55% by weight solution in the new process. The alkali hydroxide or alkali hydroxide solution used may have been produced in the case of sodium hydroxide or sodium hydroxide solution, for example, according to the amalgam procedure or the so-called membrane procedure. Both procedures have been used for a long time and are familiar to the expert. Preferably, the one produced according to the membrane process is used in the case of sodium hydroxide solution.

The aqueous phase in the process according to the invention for manufacturing polycarbonates contains alkali hydroxide solution, one or several diphenols and water, the concentration of this aqueous solution being able to vary with respect to the sum of the diphenols, not calculated as sodium salt but as free diphenol, preferably between 1% and 30% by weight, especially preferably between 3% and 25% by weight, based on the total weight of the aqueous solution. The concentration of this aqueous solution with respect to the sum of the diphenols can vary between 3% and 8% by weight for polycarbonates with an Mw greater than 45,000 gmol-1 and between 12% and 22%. % by weight for polycarbonates with an Mw of 45000 or less. In this regard it may be necessary in case of higher concentrations to temper the solutions. The alkali hydroxide used for the dissolution of the diphenols, for example sodium or potassium hydroxide, can be used solidly or as a corresponding aqueous alkali hydroxide solution. The concentration of the alkali hydroxide solution is adjusted to the target concentration of the intended diphenyl solution, however it is generally between 5% and 25% by weight, preferably 5% and 10% by weight with with respect to the 100% alkaline hydroxide solution, or more concentrated is selected and then diluted with water. In the case of the subsequent dilution process, alkaline hydroxide solutions with concentrations between 15% and 75% by weight, preferably 25% and 55% by weight, if necessary, are used. The alkaline content per mole of diphenol depends on the structure of the diphenol, however moving from 0.25 mol of alkali / mol of diphenol as a rule to 5.00 mol of alkali / mol of diphenol, preferably from 1.5 to 2 , 5 mol of alkali / mol of diphenol and in the especially preferred case that bisphenol A is used as the only diphenol of 1.85 to 2.15 mol of alkali. If more than one diphenol is used then these can be dissolved together. Since the solubility of diphenols is highly dependent on the amount of alkali used, it may be advantageous, however, instead of having a solution with two diphenols, two solutions each with a diphenol dissolved in a suitable alkaline hydroxide solution, which are then dosed separately, so that it produces the correct mixing ratio. It may also be advantageous to dissolve diphenol or diphenols not in alkaline hydroxide solution but in diluted diphenol solution, provided with additional alkali. The dissolution processes can start from solid diphenol, in most cases in flakes or tablets, or also from molten diphenol. The alkali hydroxide or alkali hydroxide solution used may have been produced in the case of sodium hydroxide or sodium hydroxide solution, for example, according to the amalgam procedure or the so-called membrane process. Both procedures have been used for a long time and are familiar to the expert. In the case of sodium hydroxide solution, one produced according to the membrane process is preferred.

In an aqueous solution of this type and / or the aqueous phase are diphenol or diphenols in whole or in part in the form of the corresponding alkaline salts or dialkaline salts.

The reaction b) can be accelerated, in the manufacture of diaryl carbonates, by catalysts, such as tertiary amines, N-alkylpiperidines or onium salts. Preferably tributylamine, triethylamine and N-ethylpiperidine are used.

The amine catalyst used in this case can be open chain or cyclic, triethylamine and ethylpiperidine are especially preferred. The catalyst is used in the new process preferably as a 1% to 55% solution by weight.

By "onium salts" are understood herein to be compounds such as NR4X, where R may be an alkyl and / or aryl moiety and / or an H and X being an anion.

The phosgene can be used in the process step b) in a liquid manner, in the form of a gas or dissolved in an inert solvent.

The inert organic solvents that can preferably be used in the new process in step b) are for example dichloromethane, toluene, the various dichloroethanes and chloropropane, chlorobenzene and chlorotoluene compounds. Dichloromethane is preferably used.

The reaction process of step b) is preferably carried out continuously and especially preferably in a piston flow with low remixing. Consequently, this can be carried out, for example, in tubular reactors. The mixing of two phases (aqueous and organic phase) can be carried out by means of built-in tubular mixers, static mixers and / or for example pumps.

The reaction according to step b) is carried out in the manufacture of diaryl carbonates, especially preferably in two stages.

In the first stage of the preferred process, the reaction is initiated by contacting the phosgene educts, the inert solvent, which preferably serves initially as the solvent for the phosgene, and the monophenol, which is preferably dissolved before in the alkali hydroxide solution. . The residence time is usually in the first stage in the range of 2 seconds to 300 seconds, especially preferably in the range of 4 seconds to 200 seconds. The pH value of the first stage is adjusted by the ratio of alkali hydroxide / monophenol / phosgene solution preferably so that the pH value is in the range of 11.0 to 12.0, preferably 11.2 to 11.8, especially preferably in 11.4 to 11.6. The reaction temperature of the first stage is maintained by cooling preferably below 40 ° C, especially preferably below 35 ° C.

In the second stage of the preferred process, the reaction to give diaryl carbonate is completed. The residence time is in the case of the preferred procedure from 1 minute to 2 hours, preferably from 2 minutes to 1 hour, very particularly preferably from 3 minutes to 30 minutes. In the second stage of the preferred process it is regulated by permanent controls of the pH value (it is measured in the continuous process preferably in line according to the basically known procedure) and the corresponding adjustment of the pH value by the addition of the alkali hydroxide solution. The amount of alkaline hydroxide solution fed is specially adjusted so that the pH value of the reaction mixture in the second process step is in the range of 7.5 to 10.5, preferably 8 to 9.5 , very especially preferably from 8.2 to 9.3. The reaction temperature of the second stage is maintained by cooling to preferably below 50 ° C, especially preferably below 40 ° C, very especially preferably below 35 ° C.

However, the general parameters or explanations set forth in this application or set forth in preferred intervals may in any way also be combined with each other, that is between the respective intervals and the preferred intervals.

In the preferred process for manufacturing diaryl carbonates, step b) phosgene with respect to monophenol is used in the mole ratio of 1: 2 to 1: 2.2. The solvent is mixed so that the diaryl carbonate is present in a 5% to 60% solution, preferably a 20% to 45% solution after the reaction.

Suitable catalysts for the process according to the invention for manufacturing diaryl carbonates are preferably tertiary amines, such as, for example, triethylamine, tributylamine, trioctylamine, N-ethylpiperidine, N-methylpiperidine or Ni / n-propylpiperidine, quaternary ammonium salts such as hydroxide, chloride , bromide, hydrogen sulfate or tetrabutylammonium tetrafluoroborate, tributylbenzylammonium, tetraethylammonium as well as the phosphonium compounds corresponding to the aforementioned ammonium compounds. These compounds are described in the literature as typical interface catalysts, are obtained commercially and are familiar to the expert. The catalysts can be added individually, in admixture or also next to each other and successively to the process according to the invention, possibly also before phosgenation, however dosages are preferred after phosgene incorporation, unless an onium compound is used ( ie, ammonium or phosphonium compound) or mixtures of onium compounds as catalysts. In the case of a

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Onium salt catalysis of this type is preferred an addition before phosgene dosing. The dosage of the catalyst or catalysts can be carried out in substance, in an inert solvent, preferably the one or those of the organic phase in case of the synthesis of diaryl carbonate, or also as an aqueous solution. In the case of the use of tertiary amines as a catalyst, for example, they can be dosed in aqueous solution such as their ammonium salts with acids, preferably mineral acids, especially hydrochloric acid. With the use of several catalysts or the dosing of partial amounts of the total amount of catalyst, different dosage modes can also be carried out at different sites or at different times. The total amount of the catalysts used is between 0.0001% in mol and 1.0% in mol, preferably between 0.001% and 0.2% in mol, with respect to the moles of monophenols used.

For the formation of monophenolate, preferably 1 mol of alkali / mol of monophenol to 5.00 mol of alkali / mol of monophenol is used, especially preferably 1.1 to 2.5 mol of alkali / mol of monophenol. The dissolution processes can start from solid phenol or molten phenol. The alkali hydroxide or alkali hydroxide solution used may have been produced in the case of sodium hydroxide or sodium hydroxide solution for example according to the amalgam procedure or the so-called membrane process. Both procedures have been used for a long time and are familiar to the expert. It is preferably used in the case of sodium hydroxide solution that produced according to the membrane process.

In an aqueous solution of this type and / or the aqueous phase, the monophenol or the monophenols are in whole or in part in the form of the corresponding alkaline salts.

In the process according to the invention, one or more pumps are used for the mixture of the organic and aqueous phase and the oligomerization stage or the step of manufacturing of aryl esters of the previous chloroformic acid. Several pumps can be used especially on an industrial scale for capacity reasons. In the case of the use of several pumps, they can be connected both in parallel and in series. A parallel connection of several pumps would be preferred. The pump assumes in the process according to the invention the function of a mixing apparatus for mixing the organic and aqueous phase to manufacture a corresponding emulsion, the function of reaction space for the formation of the oligocarbonates as well as the function of the continuous transport of the product of reaction.

The pumps used according to the invention work according to the stator-rotor principle. Accordingly, in the case of mixing the two phases, energy is especially incorporated by shearing into the reaction mixture. Because of this, the resulting emulsion has a sufficiently large interface, so that an optimal reaction can be performed at this interface.

In the case of the pumps used according to the invention, the pump housing preferably drives the stator and one or more rotors are located inside the pump. In the case of several rotors, these are preferably mounted on the same rotor shaft. In the case of the pumps used according to the invention, they are preferably centrifugal pumps. In preferred embodiments these are those centrifugal pumps whose rolling wheel (rotor) has a peripheral construction form (peripheral wheel pump). In additional preferred embodiments these are those pumps whose rolling wheel (rotor) has a radial construction form (radial wheel pump). Especially preferred according to the invention are pumps that work according to the principle of the peripheral wheel pump. The expert knows such centrifugal pumps and their modes of operation (see, for example. DE 42 20 239 A1) and are obtained commercially. The principle of a pump used according to the invention of this type is shown by way of example and schematically in Figure 1. Both embodiments with a single or with multiple separating vessels, such as double separating vessels, are suitable.

Figure 1: Schematic representation of the principle of a peripheral wheel pump with internal rotating device

The abbreviations used in Figure 1 represent

1 phosgene / solvent inlet flow

2 inlet flow of sodium monophenolate solution or aqueous / alkaline sodium bisphenolate solution

3 sodium hydroxide solution inflow (NaOH inflow)

4

discharged reaction mixture

R

internal rotating device

S

internal rotating device blades

K

circulation channel

RZ

reaction inlet side (suction side)

RA

reaction output side (discharge side)

8

10

fifteen

twenty

25

30

35

40

Four. Five

P static housing of the peripheral wheel pump with internal rotating device

The peripheral wheel pump shown in Figure 1 has a static housing P, an internal rotating device R with blades S (configured in this case as a blade wheel) and a channel K that circulates in the housing resulting therefrom from the suction side to discharge side. The peripheral pump can create relatively large pressures for a flow pump in case of small flow rates and small construction form. During transport, the reaction mixture transported between the blades S supplies its energy to the reaction mixture transported in the circulation channel. The pressure increase is carried out by impulse exchange, supplying the fluid that circulates with greater speed in the blades of the treadmill the energy to the fluid that rotates with less speed in the circulation channel.

The pumps used according to the invention can be thermostatted, that is to say they have an inlet and an outlet for a thermostated fluid. In this regard, the circulation space for this thermostated liquid and the reaction space for the reaction product are separated from each other, so that no exchange of substances can be carried out but a heat exchange is possible.

The pumps used according to the invention have as feed into the reaction space at least one input for the organic and aqueous phase as well as at least one output for the reaction mixture containing oligocarbonates (in the case of the manufacture of polycarbonates), or for the reaction mixture formed in the 1st stage in the case of the manufacture of diaryl carbonates (see Figure 1). In preferred embodiments, other inputs are preferred for the additional alkali hydroxide solution and / or diphenol solution (ato) or monophenol solution (ato) and possibly for chain switches and branching. The catalyst is preferably added at a later time to a waiting reactor subsequently connected. A schematic exemplary construction for a reaction process according to the invention of this type is shown in Figure 2. The representation in Figure 2 must be contemplated with respect to the number of waiting reactors subsequently connected only by way of example. More or less of two waiting reactors can also be connected later.

Figure 2: Schematic construction for the manufacture of polycarbonate or diaryl carbonate according to the interface procedure with the use of a peripheral wheel pump

The abbreviations used in Figure 2 represent

one

phosgene / solvent inlet flow

2

Inlet flow of sodium monophenolate solution or aqueous / alkaline sodium bisphenolate solution

3

first inlet flow of sodium hydroxide solution (inlet stream of NaOH 1)

4

discharged reaction mixture

5

second inlet flow of sodium hydroxide solution (inlet stream of NaOH 2)

6

chain switches in the manufacture of polycarbonate or catalyst in the manufacture of carbonate

diaryl (optional)

7

catalyst

Pp

peripheral wheel pump

ST

static mixer

VR1

standby reactor 1

VR2

standby reactor 2 (optional)

Wt

heat exchanger

DEH

booster pump

TG

separating vessel

W

backwash

In another embodiment of the process according to the invention, the pump used according to the invention can also be connected after a pump transfer reactor instead of a waiting reactor. This variant of carrying out the process according to the invention would have the advantage that existing installations could be used by interleaving a pump used according to the invention, without extensive modifications in the installations. A schematic example construction for a reaction process according to the invention of this type is presented in Figure 2a. The representation in figure 2a must be considered with respect to the number

fifteen

25

35

Four. Five

of waiting reactors subsequently connected only by way of example. More or less of two waiting reactors can also be connected later.

In a process variant with a pump transfer reactor subsequently connected to the pump used according to the invention, the educts, such as diphenolate solution or monophenolate solution or the first inlet flow of sodium hydroxide solution, can Either they can be added completely to the pump or they can be supplied in a proportional way only to the pump transfer reactor connected later.

Figure 2a: Schematic construction for the manufacture of polycarbonate or diaryl carbonate according to the interface procedure with the use of a peripheral wheel pump with a pump transfer reactor connected afterwards

The abbreviations used in Figure 2a in addition to those in Figure 2 represent

2'

Optional input flow of a percentage of sodium monophenolate solution or bisphenolate solution of

aqueous / alkaline sodium

3'

optional input flow of a percentage of the first input flow of sodium hydroxide solution (flow

NaOH 1 ’)

EG

degassing vessel

UR

pump transfer reactor

AT

discharge pump

P

pump to maintain circulation

The waiting time for the reaction mixture in the pump used according to the invention is preferably from 20 seconds to 10 minutes, especially preferably from 30 seconds to 5 minutes and very especially preferably from 30 seconds to 3 minutes.

To regulate the molecular weight of the polycarbonate, it may be necessary to add one or more monofunctional chain switches, such as phenol or alkylphenols, especially phenol, p-tert-butylphenol, isooctylphenol, cumylphenol, its chlorocarboxylic acid esters or acid chlorides of monocarboxylic acids or mixtures of these chain switches. Such chain switches are optionally fed either with the dihydroxydiarylalkane or the dihydroxydiarylalkanes to the reaction or added at any time to the synthesis, while phosgene or terminal groups of chlorocarboxylic acids are present in the reaction mixture or in the case of acid chlorides and chlorocarboxylic acid esters as chain switches while sufficient phenolic end groups of the polymer being formed are available. Preferably, the chain switch (s) are added, however, after phosgenation at a site or at a time when phosgene is no longer present, however the catalyst has not yet been dosed, that is, they can be dosed before the catalyst, together with the catalyst or parallel to it.

In the same way, one or more branching or branching mixtures may be added to the synthesis in the manufacture of polycarbonates. Typically, such ramifiers are added, however, before the chain switch or chain switches. For example, trisphenols, tetraphenols, acid chlorides of tri or tetracarboxylic acids or mixtures of polyphenols or acid chlorides are used as branching agents.

Examples of suitable compounds as branching agents with three or more of three phenolic hydroxyl groups are floroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -hepten-2-o, 4,6-dimethyl- 2,4,6-tri- (4-hydroxyphenyl) -heptane, 1,3,5-tri- (4-hydroxyphenyl) -benzene, 1,1,1-tri- (4-hydroxyphenyl) -ethane, tri- (4 -hydroxyphenyl) -phenylmethane, 2,2-bis- (4,4-bis- (4-hydroxyphenyl) cyclohexyl] -propane, 2,4-bis- (4-hydroxyphenyl-isopropyl) -phenol, tetra- (4- hydroxyphenyl) -methane.

Examples of other suitable trifunctional compounds as branching agents are 2,4-dihydroxybenzoic acid, trimesic acid, cyanuryl chloride and 3,3-bis- (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole.

Especially preferred branching agents are 3,3-bis- (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole and 1,1,1-tri- (4-hydroxyphenyl) -ethane.

Suitable catalysts for the process according to the invention for manufacturing polycarbonates are preferably tertiary amines, such as triethylamine, tributylamine, trioctylamine, N-ethylpiperidine, N-methylpiperidine or Ni / n-propylpiperidine, quaternary ammonium salts such as hydroxide, chloride, bromide , tetrabutylammonium hydrogen sulfate or tetrafluoroborate, tributylbenzylammonium, tetraethylammonium as well as the phosphonium compounds corresponding to the aforementioned ammonium compounds. These compounds are described in the literature as typical interface catalysts, are obtained commercially and are familiar to the expert. The catalysts can be added individually, in mixture or also one next to the

10

twenty

25

30

35

other and successively to the process according to the invention, possibly also before phosgenation, however dosages are preferred after the incorporation of phosgene, unless an onium compound (i.e. ammonium or phosphonium compound) or mixtures of compounds of onio as catalysts. In the case of catalysis with onium salt of this type, an addition is preferred before dosing phosgene. The dosage of the catalyst or catalysts can be carried out in substance, in an inert solvent, preferably the one or those of the organic phase in the case of polycarbonate synthesis, or also as an aqueous solution. In the case of the use of tertiary amines as a catalyst, for example, they can be dosed in aqueous solution such as their ammonium salts with acids, preferably mineral acids, especially hydrochloric acid. With the use of several catalysts or the dosing of partial amounts of the total amount of catalyst, different dosage modes can of course also be performed at different sites or at different times. The total amount of the catalysts used is between 0.001% in mol and 10% in mol, preferably between 0.01% and 8% in mol, especially preferably from 0.05% to 5% in mol with respect to the moles of diphenols used.

Oligocarbonates are preferably in the context of the invention those of general formulas (I), (II) and / or (III),

image2

in which

or

represents 0 or an integer from 1 to 20, preferably represents 0 or an integer from 1 to 12, especially preferably represents 0 or an integer from 1 to 8,

Y

represents an integer from 1 to 20, preferably from 1 to 12, especially preferably from 1 to 8, and

z

represents 0 or an integer from 1 to 20, preferably represents 0 or an integer from 1 to 12, especially preferably represents 0 or an integer from 1 to 8.

Such oligomers preferably have an average molecular weight Mw of up to 5000 g / mol, preferably up to 3500 g / mol, very especially preferably up to 2000 g / mol.

In the case of the average molecular weight indicated in the context of this application, these are average molecular weights (Mw) that were determined by gel permeation chromatography (CPG) with the use of polycarbonate as the standard. The detection of eluted signals can be performed, for example, by using the refractive index or by UV absorption in the area of for example 254 nm.

From the pump or pumps, the reaction mixture containing oligocarbonates or the reaction mixture containing aryl esters of chloroformic acid and / or diaryl carbonates is condensed in at least one reactor with the addition of additional alkaline hydroxide solution, optionally switch (s) chain and eventually at least one other catalyst to give polycarbonates or is reacted to give diaryl carbonates. In preferred embodiments, this reaction is performed in a cascade of several reactors connected one after the other. Suitable reactors for the reaction include any reactor embodiment, such as agitator vessels, tubular reactors, pump transfer reactors, their cascades or combinations thereof (see, for example, Figure 2 or Figure 5).

For the processing of the reaction mixture at least two phases, which contains at most still traces, preferably less than 2 ppm of esters of chlorocarboxylic acids, of full cure in the manufacture of polycarbonate can be decanted for phase separation. The aqueous alkaline phase is eventually, totally or partially reverted to the synthesis of polycarbonate as an aqueous phase or is fed to the wastewater processing, where the percentage of solvent and catalyst is separated and eventually returned to the synthesis of polycarbonate . In another variant of the processing, after the separation of the organic impurities, especially of solvents and polymeric residues, and possibly after the adjustment of a certain pH value, for example by the addition of sodium hydroxide solution, the salt is separated. for example, chloro-alkaline electrolysis can be fed, while the aqueous phase is eventually fed back to polycarbonate synthesis.

For the processing of the reaction mixture at least two phases, which contains at most still traces, preferably less than 2 ppm of aryl esters of chloroformic acid, of complete curing in the manufacture of diaryl carbonate can be decanted for phase separation . The aqueous alkaline phase is fed, eventually, totally or partially purified with washing phases, to the wastewater processing where the percentages of solvent and catalyst are separated by stabilizing distillation and eventually returning to the synthesis of diaryl carbonate. In another variant of the processing, after the separation of the organic impurities, especially of solvents and catalyst residues, and possibly after the adjustment of a certain pH value, for example by the addition of hydrochloric acid, the salt solution is separated which for example, chloro-alkaline electrolysis can be fed, while the aqueous phase is eventually fed back to the synthesis of diaryl carbonate.

The organic phase containing diaryl polycarbonates or carbonates can then be purified to remove alkaline, ionic or catalytic contamination in various ways known to the expert.

In general, the organic phase also contains, after one or several sedimentation processes, eventually assisted by passage through sedimentation vessels, agitator vessels, coalescers or separators.

or combinations of these measures (water can possibly be dosed in each or some separation stages possibly with the use of active or passive mixing elements) even percentages of the aqueous alkaline phase in fine drops as well as of the catalyst or catalysts. After this crude separation from the aqueous alkaline phase, the organic phase can be washed once or several times with dilute acids, mineral acids, carboxylic acids, hydroxycarboxylic acids and / or sulfonic acids. Aqueous mineral acids are especially preferred, hydrochloric acid, phosphorous acid, phosphoric acid or mixtures of these acids. In this regard, the concentration of these acids should preferably be in the range of 0.001% to 50% by weight, preferably 0.01% to 5% by weight. In addition, the organic phase can be repeatedly washed with desalted or distilled water. The separation of the organic phase, possibly dispersed with parts of the aqueous phase, after the individual washing steps occurs by means of sedimentation vessels, agitator vessels, coalescers or separators or combinations of these measures, the washing water being able to be dosed between the washing steps eventually with the use of active or passive mixing elements. In the manufacture of polycarbonate, between these washing steps or also after washing, acids may be added, preferably dissolved in the solvent on which the polymer solution is based. Preferably, gaseous hydrochloric acid, phosphoric acid or phosphorous acid are used in this case, which may also be used as mixtures. The purified polycarbonate solution thus obtained should preferably contain after the last separation process no more than 5% by weight, preferably less than 1% by weight, very especially preferably less than 0.5% by weight water.

The isolation of the diaryl carbonate from the solution can be carried out by evaporation of the solvent by means of temperature, vacuum or a hot carrier gas or preferably distillation.

The diaryl carbonates manufactured according to the process according to the invention are characterized by especially high purity (CG> 99.95%) and very good transesterification behavior, so that from this an excellent quality polycarbonate can then be manufactured.

The use of diaryl carbonates to make oligo / aromatic polycarbonates according to the melt transesterification process is known in the literature and for example described in the Encyclopedia of Polymer Science, vol. 10 (1969), Chemistry and Physics of Polycarbonates, Polymer Reviews, H. Schnell, vol. 9, John Wiley and Sons, Inc. (1964) or US-A-5 340 905.

The polycarbonate insulation of the solution can be carried out by evaporation of the solvent by means of temperature, vacuum or a hot carrier gas. Other isolation procedures are, for example, crystallization and precipitation.

If the concentration of the polycarbonate solution is carried out and possibly also the isolation of the polycarbonate by separation by distillation of the solvent, possibly by overheating and pressure reduction, then it is referred to as an "ultrafast procedure". Such a procedure is known to the expert and is described for example in "Thermische Trennverfahren", VCH Verlagsanstalt 1988, p.

114. If instead a heated carrier gas is sprayed together with the solution to be evaporated, then there is talk of a "spray evaporation / spray drying", which is described by way of example in Vauck, "Grundoperationen chemischer Verfahrenstechnik ”, Deutscher Verlag für Grundstoffindustrie 2000, 11th edition, p. 690. All these procedures are described in the patent literature and in textbooks and are familiar to the expert.

In the case of solvent removal by temperature (distillation separation) or the most technically efficient ultrafast process, highly concentrated polycarbonate melts are obtained. In the case of the ultrafast process, polymer solutions are repeatedly heated at light overpressure to temperatures above the boiling point at normal pressure and the pressure of these superheated solutions is reduced, with respect to normal pressure, then in a vessel with lower pressure , for example normal pressure. In this respect, it may be advantageous not to allow the concentration stages to become too large, or to express the overheating temperature stages in another way, but to better choose a two to four stage procedure.

From the highly concentrated polycarbonate melts thus obtained, the solvent residues can be removed or directly from the melt with evaporating extruder presses (see for example documents BE-A 866 991, EP-A 0 411 510, US-A 4 980 105, DE-A 33 32 065), thin film evaporators (see eg EP-A 0 267 025), falling film evaporators, extrusion evaporators or by friction compaction (see for example document EP- A 0 460 450), possibly also with the addition of a carrier agent, such as nitrogen or carbon dioxide or with the use of vacuum (see for example EP-A 0 039 96, EP-A 0 256 003, US- A 4 423 207), as an alternative also by subsequent crystallization (see for example DE-A 34 29 960) and / or heating separation of solvent residues in the solid phase (see for example US-A 3 986 269, DE-A 20 53 876). These procedures and the devices necessary for this are also described in the literature and are familiar to the expert.

Polycarbonate granules (when possible) can be obtained by direct centrifugal separation of the melt and subsequent granulation or by the use of discharge extruder presses from which most of the water is removed by centrifugation, in air or with liquid. If extruder presses are used then additives can be added to the polycarbonate melt before the extruder press, possibly with the use of static mixers or by side extruder press in this extruder press.

Alternatively, the polycarbonate solution can be subjected to spray evaporation. In the case of a spray, the polycarbonate solution is atomized, eventually after heating, either in a container with partial vacuum or it is atomized by means of a nozzle with a heated carrier gas, for example nitrogen, argon or hydrogen vapor in a container With normal pressure. In both cases it is obtained, depending on the concentration of the polymer solution, powder (diluted) or flakes (concentrated) of the polymer, from which the last remains of the solvent should also be removed as before. Granules can then be obtained by means of a composite extruder and subsequent centrifugal separation. Also in this case additives, as described above, can be added to the periphery or the extruder press itself. It may often be necessary to perform a step of compacting the polymer powder before extrusion due to the low bulk density of the powder and flakes.

Alternatively, the polymer of the washed polycarbonate solution can be precipitated to a large extent and eventually still concentrated by the addition of a non-solvent for polycarbonate. The non-solvent acts in this respect as a precipitation agent. According to this, it is advantageous to add a low amount of the non-solvent first and, if necessary, also introduce waiting times between the additions of the non-solvent charges. In addition it can be advantageous to use various non-solvents. In this case, aliphatic or cycloaliphatic hydrocarbons, especially heptane, i-octane or cyclohexane, alcohols such as methanol, ethanol or i-propanol, ketones, such as acetone, or mixtures thereof, are used as precipitation agents. In the case of precipitation, the polymer solution is usually added slowly to the precipitation agent. The polycarbonates thus obtained are processed as described in case of spray evaporation to give a granulate and eventually additives are added.

According to other procedures, precipitation and crystallization products or amorphous solidified products are crystallized in the form of a fine grain by passing vapors of one or more non-solvents for polycarbonate, with simultaneous heating below the glass transition temperature and subsequently condensed to give higher molecular weights In this regard, if they are oligomers, possibly with different terminal groups (phenolic and interrupting the chain), then there is talk of solid phase condensation.

The addition of additives serves to prolong the period of use or to improve color stability (stabilizers), for the simplification of processing (eg mold release agents, flow promoting agents, antistatic agents) or for adaptation of the properties of polymers in certain loads (impact resistant modifiers, such as rubbers; flame retardants, colorants, glass fibers).

These additives can be added individually or in any mixture, together or in several different mixtures of the polymer melt. This can be done directly in case of polymer isolation or after melting the granulate in a so-called composite stage. In this regard, the additives or mixtures thereof may be added as a solid, preferably as a powder, or as a melt to the polymer melt. Another type of dosage is the use of basic mixtures or mixtures of basic mixtures of additives or mixtures of additives.

Suitable additives are described, for example, in "Additives for Plastics Handbook, John Murphy, Elsevier, Oxford 1999", in "Plastics Additives Handbook, Hans Zweifel, Hanser, München 2001".

Suitable antioxidants or thermal stabilizers are for example:

alkylated monophenols, alkylthiomethylphenols, hydroquinones and alkylated hydroquinones, tocopherols, hydroxylated thiodiphenyl ethers, alkylidene bisphenols, O-, Ny S-benzyl compounds, hydroxybenzylated malonates, aromatic hydroxybenzyl compounds, triazine compounds, 3,5-acyl di-diols -terc-butyl-4-hydroxyphenyl) propionic, esters of β- (5-tert-butyl-4-hydroxy-3-methylphenyl) propionic acid, esters of β- (3,5-dicyclohexyl-4-hydroxyphenyl) propionic acid, esters of 3,5-di-tert-butyl-4-hydroxyphenylacetic acid, amides of β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acids, suitable thiosynergic compounds, secondary antioxidants, phosphites, phosphonites, phosphonates and phosphanes , benzofuranones or indolinones.

Preferred antioxidants or thermal stabilizers are phosphites, phosphonates and organic phosphanes, in most cases those in which the organic moieties are wholly or partially composed of eventually substituted aromatic moieties.

Suitable complexing agents for heavy metals and for the neutralization of alkaline traces are, for example, o-or m-phosphoric acids, phosphates or phosphites totally or partially esterified.

Suitable light-protecting agents (UV absorber) are, for example, 2- (2'-hydroxyphenyl) benzotriazoles, 2-hydroxybenzophenones, esters of substituted and unsubstituted benzoic acids, acrylates, sterically hindered amines, oxamides, 2- ( 2-hydroxyphenyl) -1,3,5-triazines or substituted benzotriazoles, with substituted benzotriazoles being especially preferred.

Polypropylene glycols can be used alone or in combination with, for example, sulfones or sulfonamides as stabilizers against gamma ray deterioration.

These and other stabilizers can be used individually or in combination and can be added to the polymer in the aforementioned forms.

In addition, processing aids can be added as mold release agents, such as derivatives of long chain fatty acids. For example, pentaerythritol tetraestearate and glycerin monostearate are preferred. They are used alone or in a mixture preferably in an amount of 0.02% to 1% by weight with respect to the mass of the composition. Suitable flame retardant additives are phosphate esters, ie triphenyl phosphate, resorcinadiphosphoric acid esters, bromine-containing compounds, such as brominated phosphoric acid esters, brominated oligocarbonates and polycarbonates, as well as preferably salts of fluorinated organic sulfonic acids. Agents that confer adequate impact toughness are butadiene rubber with styrene-acrylonitrile or grafted methyl methacrylate, ethylene-propylene rubbers with grafted maleic acid anhydride, ethyl acrylate and butyl rubbers with methyl methacrylate or grafted styrene-acrylonitrile, interpenetrating siloxane and acrylate networks with grafted methyl methacrylate or styrene acrylonitrile.

In addition, dyes, such as organic dyes or pigments, as well as inorganic pigments, IR absorbers, can be added individually, in admixture or also in combination with stabilizers, glass fibers, glass (hollow) spheres or inorganic fillers.

Polycarbonate melts, which were generated by insulating the polymer or by preparing a mixture, can be separated by centrifugation using a rope-shaped nozzle head, cooled with gas, for example air or nitrogen, or a cooling liquid In most cases, water and solidified ropes are granulated in regular granulators with blades that are, for example, in a rotating roller, in air, with inert gas such as nitrogen or argon or with water. According to each technical embodiment, granules in the form of a column with round or elliptical cross-section and rough or smooth surface are produced in this regard. The edges may be smooth or have glassy crevices with broken edges or remains detained at the edges. A granulate shaped as uniformly as possible with protrusions that remain as little as possible at the edges is desirable. In addition, the percentage of powder in the granulate should be kept as low as possible, preferably below 100 mg / kg of granulate. The diameter of the granules must be between 0.5 mm and 10 mm, preferably 1 mm to 8 mm, especially preferably 3 mm to 6 mm. While the length of the granules should be found between 1 mm and 10 mm, preferably between 2 mm and 8 mm and the weight between 10 mg and 50 mg, preferably between 15 mg and 30 mg. A granulate whose proportion of diameter is preferred, in case of elliptical cross-section of the average diameter, with respect to the length amounts to 0.8 to 1.2, especially preferably one with the proportion of approximately 1. These parameters are subject to size distributions, distributions as narrow as possible are preferred, that is, granules sized as uniformly as possible.

Cooling, centrifugal separation, granulation and subsequent transport or advance of the granulate with gas or liquid are configured, and subsequent storage, possibly according to a mixing or homogenization procedure, so that no possible application is made. impurity on the surface of the polymer, rope or granules despite the static charge that may exist, such as dust, cisco machines, aerosol lubricants and other liquids, as well as possibly used refrigeration salts or water baths.

Polymers manufactured according to the process according to the invention are also the subject of the present application.

The polymers manufactured according to the process according to the invention have a narrow molecular weight distribution, preferably even narrower than those manufactured according to the state of the art with the interface process. The polymers manufactured according to the process according to the invention preferably have an irregularity U of 1.1 to 1.6 (according to each viscosity of the manufactured polycarbonates).

The polycarbonates manufactured according to the invention are suitable, for example, for manufacturing extrudates and molded parts, especially those for use in transparent product line, especially in line of optical application products such as plates, ribbed plates, glazing, dispersion crystals, lamp protectors or optical data memory, such as audio CD, CD-R (W), DVD, DVD-R (W), mini-discs in their different embodiments only readable or that can be recorded once possibly also that they can be recorded repeatedly.

Other applications are, for example, without limiting the object of the present invention:

one.

safety glasses, which are necessary as is known in many areas of buildings, vehicles and airplanes, as well as helmet protectors.

2.

sheets

3.

blown parts (see also US-A 2 964 794), for example 1 to 5 gallon water bottles.

Four.

transparent plates, such as solid plates or especially hollow chamber plates, for example to cover buildings such as train stations, greenhouses and lighting installations.

5.

optical data memories, such as audio CD, CD-R (W), DCD, DVD-R (W), mini-discs and subsequent developments

6.

lamp housings or traffic signs

7.

foams with open or closed surface, if possible printable

8.

threads and filaments (see also document DE-A 11 37 167)

9.

lighting applications, possibly with the use of glass fibers for online applications of translucent products

10.

translucent configurations with a content of barium sulfate and titanium dioxide and or zirconium oxide or organic polymeric acrylate rubbers (EP-A 0 634 445, EP-A 0 269 324) for manufacturing transparent or light dispersive molded parts.

eleven.

precision injection molded parts, such as supports, for example lens holders; in this case polycarbonates with glass fibers and an optionally additional content of 1-10% by weight of molybdenum disulfide (with respect to the entire formed mass) are used.

12.

optical equipment parts, especially lenses for photo and video cameras (document DE-A 27 01 173).

13.

light transmission brackets, especially light conductive cables (EP-A 0 089 801) and lighting strips

14.

electro-insulating materials for electrical conductors and for outlet boxes and plug connectors as well as capacitors.

fifteen.

mobile phone cases.

16.

network interface devices

17.

support materials for organic photoconductors

18.

lamps, headlight bulbs, light dispersive crystals or internal lenses.

19.

Medical applications such as oxygenators, dialyzers.

twenty.

Food applications, such as bottles, crockery and chocolate molds.

twenty-one.

online applications of car products, such as glazing or in the form of combinations with ABS as bumpers.

22

sports items such as slalom poles, ski boot buckles.

2. 3.

household items such as sinks, sinks, mailboxes

24.

housings, such as electrical distribution panels

25.

housings for electrical appliances such as toothbrushes, hair dryers, coffee machines, machine tools, such as drills, milling machines, planers and saws

26.

washing machine hatches

27.

goggles, sunglasses, corrective glasses or their lenses.

28.

lamp protectors

29.

packing sheets

30

chip boxes, chip holders, silicon wafer boxes

31.

other applications such as barn feeding doors or animal cages.

Surprisingly, the diphenol load or monophenol load of the wastewater could also be reduced with the process according to the invention. The use of pumps with triple function as a mixing unit, reaction space for the oligomerization stage

or manufacturing step of aryl esters of chloroformic acid and / or diaryl carbonates as well as transport unit is not described in the literature for the interface process for manufacturing diaryl polycarbonates or carbonates. Therefore, it is also the object of the present invention to use one or more pumps to continuously produce polycarbonate or diaryl carbonate according to the interface procedure, in which the pump (s)

- works (works) according to the stator-rotor principle

- can (can) be thermostatted and

-presents (presents) at least respectively one input for an organic and an aqueous phase and possibly other inputs for chain switches, branching agents and / or additionally alkaline hydroxide solution, catalyst as well as at least one outlet for the mixture containing oligocarbonates or mixture containing aryl esters of chloroformic acid and / or diaryl carbonates,

characterized in that in this / these pumps / pumps the continuous mixing of the organic and aqueous phase is carried out, the organic phase containing at least one solvent suitable for the polycarbonate or diaryl carbonate and totally or partially the phosgene and containing the aqueous phase the or diphenol (s) or monophenol (s), water and alkali hydroxide solution, such as the reaction of or of diphenol (s) or monophenol (s) and phosgene to give oligocarbonates or aryl esters of chloroformic acid and / or carbonates of diaryl.

The pumps described above for the process according to the invention are suitable for this use. Especially suitable for this are centrifugal pumps, particularly preferably peripheral wheel pumps.

The following examples serve to explain the invention by way of example and should not be construed as limiting.

Examples

In a continuous interphase process, polycarbonates were manufactured using respectively different reactor concepts. In the tests the influence of the use according to the invention of the special pump with respect to the reactors known as pump transfer reactors or nozzles in otherwise equal reaction settings was tested.

The reaction was carried out in all examples continuously in an emulsion of water and a solvent mixture of 50% by weight of methylene chloride and 50% by weight of chlorobenzene. As a chain switch, p-tert-butylphenol (BUP) was used. As catalyst n-ethylpiperidine (EPP) was used. Polycarbonate solution

10

fifteen

twenty

25

30

35

40

Four. Five

obtained after the separation of the aqueous phase after crossing the waiting cascade composed of the four rear reactors NR1 to NR4 in Figures 3 and 5 was washed acidically with hydrochloric acid, and then by means of disk-shaped separators was washed neutrally with completely desalinated water. The polycarbonate solutions washed in this way were concentrated to dryness by evaporation of the solvent. A complete removal of the residual solvent in the vacuum oven at 100 ° C led to the polycarbonate.

The embodiment was carried out in all examples with the following reaction settings:

•

Na bisphenolate solution: flow rate 910.3 g / h (0.598 mol of bisphenol A / h), Na bisphenolate content: 15.0% by weight of Na bisphenol with respect to the total weight of the solution

•

Phosgene: 72.18 g / h (0.73 mol / h)

•

Solvent: 737.7 g / h (solvent mixture consisting of 50% by weight of methylene chloride and 50% by weight of chlorobenzene)

•

Sodium hydroxide solution: 113.9 g / h; NaOH content: 44% by weight of NaOH, based on the total weight of the sodium hydroxide solution, to dissolve 136.5 g of bisphenol A

•

Sodium hydroxide solution after the first reactor: 49.5 g / h; NaOH content: 44% by weight of NaOH with respect to the molecular weight of the sodium hydroxide solution

•

BUP chain switch: 3,594 g / h (in 140.2 g / h of solvent mixture 50:50)

•

EPP catalyst: 0.677 g / h; (in 6.2 g / h of 50:50 solvent)

•

Phosgene / bisphenol A: 122% in mole of phosgene with respect to the amount of bisphenol A substance

•

EPP / bisphenol A: 1.0% in mol of EPP with respect to the amount of bisphenol A substance

•

BUP / bisphenol A: 4.0% in mol of BUP with respect to the amount of bisphenol A substance

•

Reaction temperature: 34 ° C

•

Polycarbonate content: 15.0% by weight of polycarbonate, based on the total weight of the solution, dissolved in solvent mentioned above

•

Adding the chain switch after the first reactor

The chain switch was added in all the examples so that a comparable relative viscosity (ηrel) was obtained for the final products.

Example 1 (comparative example):

According to the test construction in Figure 3, polycarbonate was manufactured. In this regard, a UR 2 pump transfer reactor of this type according to Figure 4 composed of glass was used as the first reactor, to which a waiting cascade of four stirring vessels (subsequent reactors NR1 to NR4) was connected for the reaction later. In the individual reactors, the stirring elements were driven by M motors. Before and after the last subsequent reactor NR4 there were also two cogwheel pumps with an M motor. The solution of Na bisphenolate, phosgene in the solvent and the hydroxide solution of Sodium mentioned above were fed in the aforementioned amount continuously to the pump transfer reactor and was remixed by pump transfer with the valve V7.3 open. In this regard, the agitator used in the pump transfer reactor was driven at 1000 revolutions / min. At the outlet of the pump transfer reactor, the reaction mixture was conducted continuously outside the pump transfer reactor, mixed with the chain switch and led to the waiting cascade shown in Figure 3 of four stirring vessels. for the subsequent reaction. The catalyst was fed to the third subsequent reactor NR3.

Example 2 (comparative example):

The same test construction as in example 1 was used, however valve V7.3 was closed in the UR 2 pump transfer reactor, so that a remixing was removed. Because of this, the UR 2 pump transfer reactor acted as a normal nozzle.

Example 3 (according to the invention):

Instead of the UR 2 pump transfer reactor in example 1 an RM peripheral wheel pump according to figure 1 was used. Otherwise the same test construction as in example 1 was used (see figure 5). The Na bisphenolate solution, phosgene in the solvent and the sodium hydroxide solution mentioned above were fed in the aforementioned amount continuously to the RM pump and mixed by means of the rotating peripheral wheel provided with blades. At the outlet of the RM pump the reaction mixture was conducted continuously outside the internal space of the pump, mixed with the chain switch and led to the waiting cascade shown in Figure 5 of four stirring vessels for the reaction later. The catalyst was fed to the third subsequent reactor NR3.

Table 1 shows the results with respect to the polycarbonate obtained as well as the resulting residual water load with bisphenol A (BPA).

Table 1:

Example

BPA content in wastewater [ppm by weight] Mw [g / mol] OR ηrel

one

238 19182 1.54 1,215

2

675 19111 1.69 1,214

3

48 19353 1.51 1,218

The relative solution viscosity ηrel was determined in dichloromethane as a solvent at a concentration of 5 g / l and at a temperature of 25 ° C with a Ubbelohde viscometer.

10 The BPA content in the wastewater was determined by means of HPLC and UV detection (245 nm) after calibration with BPA.

The results show a clear reduction in the residual water load with BPA in case of the use according to the invention of the special pump with respect to conventional manufacturing by means of the pump transfer reactor or a simple nozzle. In the case of the embodiment according to the invention the interface procedure is not

Therefore, an increase in the addition of phosgene and sodium hydroxide solution is necessary to complete the diphenol reaction. Therefore the process carried out according to the invention is also cheaper than according to known procedures. Also the irregularity U, which is a measure of the extent of the molecular weight distribution of the resulting polycarbonate, could be slightly reduced with respect to the products obtained according to known procedures.

twenty

Claims (18)

1. Process for continuously manufacturing polycarbonates or copolycarbonates or diaryl carbonates according to the interphase process from at least one diphenol or monophenol, phosgene and at least one catalyst if necessary in the presence of at least one chain switch and / or branching , characterized in that

(to)

a mixture of the organic and aqueous phases is continuously generated, the organic phase containing at least one solvent suitable for polycarbonate or diaryl carbonate and totally or partially the phosgene and the aqueous phase containing the diphenol (s) or monophenol (s), water and alkali hydroxide solution,

(b)

a reaction of the diphenol (s) or monophenol (s) and phosgene is carried out to give oligocarbonates or to give aryl esters of chloroformic acid or diaryl carbonates or a mixture of aryl esters of chloroformic acid and diaryl carbonates,

(C)

the oligocarbonates or aryl esters of the chloroformic acid and / or diaryl carbonates are then reacted in at least one reactor with the addition of additional alkaline hydroxide solution, optionally chain switch (s) and possibly at least one other catalyst,

characterized in that the continuous mixing of the organic and aqueous phases in (a) and the reaction to give oligocarbonates or aryl esters of the chloroformic acid and / or diaryl carbonates in (b) are carried out in one or several pump (s), which - works (works) according to the stator-rotor principle -can (can) be thermostated and -presents (presents) at least respectively one input for the organic phase and the aqueous phase and possibly other inputs for the catalyst, chain switch, branching and / or additionally the alkali hydroxide solution as well as at least one outlet for the mixture that it contains oligocarbonates or of aryl esters of the chloroformic acid-diaryl carbonates.

2.

Method according to claim 1, characterized in that in step (c) at least one other catalyst is used.

3.

Method according to claim 1 or 2, characterized in that the pump (s) has other inputs for additionally the alkali hydroxide solution as well as at least one outlet for the mixture containing aryl esters of the chloroformic acid and / or daily carbonates.

Four.

Method according to one of claims 1 to 3, characterized in that the pump (s) have (have) one or more rotors.

5.

Method according to one of claims 1 to 4, characterized in that the pump (s) can be thermostated at a temperature of -5 ° C to 100 ° C, preferably 15 ° C to 80 ° C, especially preferably 25 ºC to 65 ºC.

6.

Method according to one of claims 1 to 5, characterized in that as diphenols those of general formula are used

HO-Z-OH wherein Z is a divalent organic moiety with 6 to 30 carbon atoms, which contains one or more aromatic groups.

7.

Process according to claim 6, characterized in that as diphenol (s) hydroquinone, resorcin, dihydroxy diphenyl, bis- (hydroxyphenyl) -alkanes, bis (hydroxy-phenyl) -cycloalkanes, bis- (hydroxyphenyl) sulfides, bis (hydroxyphenyl) are used -ethers, bis- (hydroxyphenyl) -ketones, bis- (hydroxyphenyl) -sulfones, bis- (hydroxyphenyl) -sulfoxides, α, α'-bis (hydroxyphenyl) -diisopropylbenzenes, bis- (hydroxyphenyl) phthalimidines or their alkylated compounds, nucleoalkylated and nucleohalogenated.

8.

Process according to claim 6, characterized in that 4,4'-dihydroxy diphenyl, 2,2-bis- (4-hydroxyphenyl) -1-phenyl propane, 1,1-bis- (4-hydroxyphenyl) are used as diphenol (s) ) -phenyl-ethane, 2,2-bis- (4-hydroxyphenyl) propane (bisphenol A, BPA), 2,4-bis- (4-hydroxyphenyl) -2-methylbutane, 1,3-bis- [2- (4-hydroxyphenyl) -2-propyl] benzene (bisphenol M), 2,2-bis- (3-methyl4-hydroxyphenyl) -propane, bis- (3,5-dimethyl-4-hydroxyphenyl) -methane, 2, 2-bis- (3,5-di-methyl-4-hydroxyphenyl) -propane, bis- (3,5-dimethyl-4-hydroxyphenyl) -sulfone, 2,4-bis- (3,5-dimethyl-4-hydroxyphenyl) ) -2-methylbutane, 1,3-bis- [2- (3,5-dimethyl-4-hydroxyphenyl) -2propyl] -benzene, 2-hydrocarbyl-3,3-bis (4-hydroxyphenyl) phthalimidine, 3, 3-bis (4-hydroxyphenyl) -1-phenyl-1H-indole-2-one, 2,2-bis (4-hydroxyphenyl) -1-phenyl-1H-indole-2-one, 3,3-bis (4- hydroxyphenyl) -1-methyl-1H-indole-2-one, 2,2-bis (4-hydroxyphenyl) -1-methyl-1Hindole-2-one, 3,3-bis (4-hydroxyphenyl) -N-methyl -phthalimidine, 3,3-bis (4-hydroxyphenyl) -N-phenyl-phthalimidine and 1,1-bis- (4-hydroxyphenyl) -3,3,5-trimethylcycloh exano (bisphenol TMC).

5 10 fifteen twenty 25 30 9. Process according to one of claims 1 to 5, characterized in that as monophenol (s) are used compounds of formula (I): image 1 wherein it is R = hydrogen, halogen or an alkoxycarbonyl moiety or C1 to C9 alkyl branched or unbranched moiety.

10.

Method according to claim 9, characterized in that phenol, cresols, pterc-butylphenol, p-cumylphenol, pn-octylphenol, p-iso-octylphenol, pn-nonylphenol and p-iso-nonylphenol, p-chlorophenol are used as monophenol (s). , 2,4-dichlorophenol, p-bromophenol and 2,4,6-tribromophenol or salicylic acid methyl ester or a mixture of these compounds.

eleven.

Method according to one of claims 1 to 10, characterized in that in the case of the pump or pumps, which are used in (a) and / or (b), it is a centrifugal pump.

12.

Method according to claim 11, characterized in that in the case of the centrifugal pump it is a peripheral wheel pump.

13.

Method according to at least one of claims 1 to 12, characterized in that the pump (s) is constructed according to the principle of one or more chambers.

14.

Use of one or more pump (s) to continuously produce polycarbonate or diaryl carbonate according to the interphase procedure, in which the pump (s) - works (operates) according to the stator-rotor principle

-can (can) be thermostated and -presents (presents) at least one entry for an organic and an aqueous phase respectively.

fifteen.

Use of one or several pump (s) according to claim 14, characterized in that other inputs for chain switches, branching and / or additionally alkali hydroxide solution, catalyst as well as at least one outlet for the mixture containing oligocarbonates or mixture are present containing aryl esters of chloroformic acid and / or diaryl carbonates.

16.

Use of one or more pump (s) according to claim 15, characterized in that in this / these pumps both the continuous mixing of the organic and aqueous phases is carried out, the organic phase containing at least one solvent suitable for the polycarbonate or diaryl carbonate and totally or partially the phosgene and containing the aqueous phase the diphenol (s) or monophenol (s), water and alkaline hydroxide solution, as well as the reaction of the diphenol (s) or monophenol (s) and phosgene to give oligocarbonates or aryl esters of chloroformic acid and / or diaryl carbonates.

17.

Use of one or several pump (s) according to one of claims 13 to 16, characterized in that in the case of the pump (s) these are centrifugal pumps.

18.

Use of one or several pump (s) according to claim 17, characterized in that in the case of the centrifugal pump (s) it is a peripheral wheel pump.