DE10248021A1 - Production of polycarbonate for use in molded or extruded products involves interfacial polymerisation with a work-up process in which a holding tank is interposed between polymer solution wash and filter - Google Patents

Abstract

A method for the production of polycarbonate (PC) by interfacial polymerisation, in which the PC solution wash is connected to a holding tank with a residence time of 30-240 minutes for the washed PC solution. Independent claims are also included for (1) polycarbonate (PC) obtained by the method; and (2) extruded and molded products containing this PC.

Description

The subject of the patent is a method for Production of polycarbonates using the so-called phase interface process characterized in that the polycarbonate solution wash is a tank with a dwell time from 30 to 240 minutes for the washed polycarbonate solution is connected downstream, the polycarbonate obtainable by this process, its use for the production of moldings and extrudates and these moldings and extrudates themselves.

In order to produce polycarbonate with the lowest possible concentration of impurities, intensive filtration of the melt is essential, as described for example in EP-A 1 199 325 or EP-A 1 156 071 , In order to reduce the load on this melt filter, ie to increase its service life, it has also proven to be advantageous to filter the washed, organic polycarbonate solution, as is the case, for example, in JP-B 3 105 324 is described.

Despite the intense washing of the polycarbonate solution with a preferably low residual water content of less than 0.5 % and a stable reaction has been repeatedly observed in the past that the filter life the filter for the isolation step of the polycarbonate fluctuations in some cases subject. Especially with fluctuations in outside temperature were frequent filter changes and disorders the result in insulation.

Hence the task to find a method to increase the service life of the solution filter and if necessary, to enable the use of filters with higher fineness. There was also the goal of containing impurities in the Reducing polycarbonate even further without using this measure having to buy unacceptably short filter life.

Surprisingly it has now been found that a tank downstream of the polycarbonate solution wash for the washed polycarbonate solution with a dwell time of 30 to 240 minutes downstream filter increased, stabilizes the operation of the isolation stage for polycarbonate and it allows the fineness of the filters to be increased. This measure will the quality The polycarbonate produced improves at the same time with less interference Driving. The tank is between the polycarbonate solution wash and the insulation switched, preferably between tank and insulation a filter stage is interposed.

In this retention tank according to the invention for the washed polycarbonate solution sits surprisingly crystallized / crystallized in the course of the dwell time of 30 to 240 minutes Polycarbonate from the bottom of the tank. These can then simply be used as sediment subtracted from. Such gel particles shorten filter life and give e.g. Defects in optical data memories made from it or other applications where optical quality is required becomes. In addition, a complete removal of such gel particles is due to their viscoelastic properties under the shear conditions at the Filtration is very difficult. This is unexpected under the shear-free conditions in the dwell tank on a larger scale possible. Furthermore, the retention tank surprisingly allows a reduction the water content of the polycarbonate solution by adding a layer of water on the surface the solution forms. This water can additionally to be withdrawn from the dwell time boiler is unfavorable to the thermal solvent separation and leads to Fluctuations in the process and increased Corrosion when using chlorinated solvents such as Methylene chloride.

The use of a polycarbonate solution retention tank therefore surprisingly leads to a quality gain and increased Operational reliability.

• – Schnell, „Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964, S. 33-70;
• – D.C. Prevorsek, B.T. Debona und Y. Kesten, Corporate Research Center, Allied Chemical Corporation, Morristown, New Jersey 07960: „Synthesis of Poly fester Carbonate) Copolymers" in Journal of Polymer Science, Polymer Chemistry Edition, Vol. 18,(1980)"; S. 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 und schließlich
• – Dres. U. Grigo, K. Kircher und P. R- Müller "Polycarbonate" in Becker/Braun, Kunststoff-Handbuch, Band 3/1, Polycarbonate, Polyacetale, Polyester, Celluloseester, Carl Hanser Verlag München, Wien 1992, S. 118–145,

The general process for the production of polycarbonate according to the phase interface process has been described in many different ways in the literature, including at

• - Schnell, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964, pp. 33-70;
• - DC Prevorsek, BT Debona and Y. Kesten, Corporate Research Center, Allied Chemical Corporation, Morristown, New Jersey 07960: "Synthesis of Poly solid Carbonate) Copolymers" in Journal of Polymer Science, Polymer Chemistry Edition, Vol. 18, (1980 ) "; Pp. 75-90,
• - D. Freitag, U. Grigo, PR Müller, N. Nouvertne ', BAYER AG, "Polycarbonates" in Encyclopedia of Polymer Science and Engineering, Volume 11, Second Edition, 1988, pp. 651-692 and finally
• - Dres. U. Grigo, K. Kircher and P. R- Müller "Polycarbonate" in Becker / Braun, plastic manual, volume 3/1, polycarbonates, polyacetals, polyester, cellulose esters, Carl Hanser Verlag Munich, Vienna 1992, p 118-145.

as well as eg in EP-A 0 517 044 and many other patent applications.

According to this method, the phosgenation of a disodium salt of a bisphenol (or a mixture of different bisphenols) in aqueous alkaline solution (or suspension) is carried out in the presence of an inert organic solvent or solvent mixture which forms a second phase. The resulting oligocarbonates, which are mainly present in the organic phase, are condensed with the aid of suitable catalysts to form high-molecular polycarbonates dissolved in the organic phase. The orga African phase is finally separated off and the polycarbonate is isolated therefrom by various workup steps.

In this process, an aqueous phase made from NaOH, one or more bisphenols and water, being the concentration of this aqueous solution in terms of the sum of the bisphenols, not as sodium salt but as free Bisphenol calculated, between 1 and 30 wt .-%, preferably between 3 and 25% by weight, particularly preferably between 3 and 8% by weight for polycarbonates with a Mw> 45000 and 12 to 22% by weight for Polycarbonates with a Mw <45000, can vary. At higher concentrations, it may be necessary the solutions to temper. That to solve the Sodium hydroxide used bisphenols can be solid or as aqueous sodium hydroxide solution be used. The concentration of the sodium hydroxide solution depends on the target concentration of the desired bisphenolate solution but generally between 5 and 25% by weight, preferably 5 and 10% by weight, or is chosen more concentrated and then with water diluted. In the process with subsequent dilution sodium hydroxide solutions with concentrations between 15 and 75 wt .-%, preferably 25 and 55 wt .-%, optionally tempered, used. The alkali content per mole of bisphenol is very different from the structure of the Dependent on bisphenols, but usually ranges between 0.25 mol alkali / mol bisphenol and 5.00 mol alkali / mol bisphenol, preferably 1.5-2.5 mol alkali / mol bisphenol and if bisphenol A is used as the sole bisphenol, 1.85-2.15 mole of alkali. If more than one bisphenol is used, these can be solved together. However, it can be advantageous to separate the bisphenols in optimal alkaline phase and the solutions metered separately or combined to feed the reaction. Farther it may be advantageous not to use the bisphenols in sodium hydroxide solution but in with additional Alkali-equipped, diluted bisphenolate to solve. The release processes can be from solid bisphenol, usually in dandruff or prill form or also from melted bisphenol. The sodium hydroxide used or the sodium hydroxide solution according to the amalgam process or the so-called Membrane processes have been produced. Both procedures will used for a long time and are familiar to the expert. Prefers caustic soda from the membrane process is used.

The aqueous phase thus prepared is combined with an organic phase consisting of solvents for polycarbonate, the opposite of the Reactants are inert and form a second phase, phosgenated.

The dosage of Bisphenol after or during phosgene introduction can be carried out for as long as phosgene or its immediate secondary products, the chlorocarbonic acid esters, present in the reaction solution are.

The synthesis of polycarbonates Bisphenols and phosgene in an alkaline environment are exothermic Reaction and is preferred in a temperature range of -5 ° C to 100 ° C 15 ° C to 80 ° C, very special preferably carried out 25-65 ° C, wherein depending on the solvent or solvent mixture possibly under pressure has to be worked.

For the production of the polycarbonates to be used according to the invention Suitable diphenols are, for example, 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, as well as their alkylated, nuclear alkylated and nuclear halogenated compounds.

Preferred diphenols are 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) -1-phenyl-propane, 1,1-bis (4-hydroxyphenyl) phenyl-ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1,1-bis (4-hydroxyphenyl) m / p diisopropylbenzene, 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, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) m / p-diisopropyl benzene and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane.

Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, 1,1-bis (4-hydroxyphenyl) phenylethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane.

These and other suitable diphenols are, for example, in the US-A 2 999 835 , 3 148 172, 2 991 273, 3 271 367, 4 982 014 and 2 999 846, in the German laid-open publications 1 570 703, 2 063 050, 2 036 052, 2 211 956 and 3 832 396, the French patent specification 1 561 518, in the monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964, pp. 28ff, 5.102ff", and in "DG Legrand, JT Bendler, Handbook of Polycarbonate Science and Technology, Marcel Dekker New York 2000, pp. 72ff. " described.

In the case of homopolycarbonates only one diphenol is used, in the case of copolycarbonates several diphenols are used, the bisphenols used, of course, as well as all other chemicals and auxiliaries added to the synthesis with those from their own synthesis, handling and storage Contaminants can be contaminated, although it is desirable is, if possible to work with clean raw materials.

The organic phase can consist of one or mixtures of several solvents consist. Suitable solvents are chlorinated hydrocarbons (aliphatic and / or aromatic), preferably dichloromethane, trichlorethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane and chlorobenzene and their mixtures. However, it can also be aromatic Hydrocarbons such as benzene, toluene, m / p / o-xylene or aromatic Ethers such as anisole alone, in a mixture or in addition or in a mixture with chlorinated hydrocarbons can be used. Another embodiment the synthesis uses solvents which Do not loosen polycarbonate but just swell. It can hence non-solvent for polycarbonate in combination with solvents be used. Then as a solvent also in the aqueous Phase soluble solvent such as tetrahydrofuran, 1,3 / 1,4-dioxane or 1,3-dioxolane can be used if the solvent partner forms the second organic phase.

The two phases of the reaction mixture form are mixed to accelerate the reaction. This happens by entering energy over Shear, i.e. Pumps or stirrers or by static mixers or by generating turbulent flow using Nozzles and / or Dazzle. Combinations of these measures are also used often also repeated in chronological or apparatus sequence. As stirrer anchor, propeller, MIG stirrers, etc. are preferably used, such as they e.g. in Ullmann, "Encyclopedia of Industrial Chemistry ", 5. Edition, Vol B2, p. 251 ff. As pumps Centrifugal pumps, often multi-stage, with 2 to 9 stages preferred are used. As nozzles and / or diaphragms are perforated diaphragms or in their place tapered pipe sections or also Venturi or Lefos nozzles used.

The entry of the phosgene can be gaseous or liquid or solved in solvent respectively. The surplus used of phosgene, based on the sum of the bisphenols used, is between 3 and 100 mol%, preferably between 5 and 50 mol%. Where about one-off or repeated replenishment of sodium hydroxide solution or corresponding replenishment of bisphenolate solution the pH of the aqueous Phase during and after phosgene dosing in the alkaline range, preferred between 8.5 and 12, while after catalyst addition should be 10 to 14. The temperature during phosgenation is 25 to 85 ° C, preferred 35 to 65 ° C, depending on the solvent used even under pressure can be worked.

The phosgene can be directly in the described mixture of organic and aqueous phases take place or also in whole or in part, before mixing the Phases, in one of the two phases, which then follows with the corresponding other Phase is mixed. Furthermore, the phosgene can be wholly or partly in a recirculated partial stream of the synthesis mixture from both phases are metered, this Partial stream is preferably recycled before the addition of catalyst. In another embodiment become the described aqueous Phase mixed with the organic phase containing the phosgene and subsequently after a residence time of 1 second to 5 minutes, preferably 3 seconds to 2 minutes the above recirculated partial flow added or the two phases, the aqueous phase described with the organic phase containing the phosgene directly in the above recirculated partial flow mixed. In all of these embodiments the pH value ranges described above must be observed and if necessary by single or multiple replenishment of sodium hydroxide solution or to comply with the corresponding dosing of bisphenolate solution. Likewise must the temperature range may be maintained by cooling or dilution become.

The implementation of the polycarbonate synthesis can happen continuously or discontinuously. The reaction can therefore in stirred tanks, Tube reactors, pump reactors or stirred tank cascades or their Combinations take place, using the aforementioned mixing elements is to make sure that watery and organic phase as possible do not separate until the synthesis mixture has reacted, i.e. no saponifiable chlorine from phosgene or chlorocarbonic acid esters contains more.

The monofunctional ones required to regulate the molecular weight Chain terminators such as phenol or Alkylphenols, especially phenol, p-tert-butylphenol, iso-octylphenol, Cumylphenol, its chlorocarbonate or acid chlorides of monocarboxylic acids or mixtures of these chain terminators are either with fed to the bisphenolate or bisphenolates of the reaction or but added at any point in the synthesis as long in the reaction mixture still phosgene or chlorocarbonic acid end groups are present or in the case of acid chlorides and chlorocarbonic acid esters sufficient as a chain terminator phenolic end groups of the polymer being formed are available. Before the chain terminator (s) are preferably after the phosgenation added at one place or at a time when no phosgene more is present, but the catalyst has not yet been dosed, or she be in front of the catalyst, together with the catalyst or in parallel dosed to it.

In the same way you might branching agents or branching mixtures of synthesis to be used added, usually but before the chain breakers. Usually trisphenols, Quarter phenols or acid chlorides of tri- or tetracarboxylic acids used, or mixtures of polyphenols or acid chlorides.

Some of the usable connections with three or more than three phenolic hydroxyl groups are, for example
phloroglucinol,
4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) heptene-2,
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,
Some of the other trifunctional compounds are 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole.

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

The one in phase interface synthesis catalysts used are tert. Amines, especially triethylamine, Tributylamine, trioctylamine, N-ethylpiperidine, N-methylpiperidine, N-i / n-propylpiperidine; quaternary Ammonium salts such as tetrabutylammonium / tributylbenzylammonium / tetraethylammonium hydroxide / chloride / bromide / -hydrogen sulfate / tetrafluoroborate; and the phosphonium compounds corresponding to the ammonium compounds. The ammonium and phosphonium compounds also become common referred to as onium compounds. These connections are typical Interfacial catalysts described in the literature, commercially available and familiar to the skilled worker. The Catalysts can individually, in a mixture or also side by side and in succession of the synthesis are added, optionally also before the phosgenation, preferably however, are dosages after phosgene entry, unless it becomes an onium compound or mixtures of onium compounds used as catalysts, then an addition before the phosgene is preferred. The metering of the catalyst or catalysts can be carried out in bulk, in an inert solvent, preferably that of polycarbonate synthesis, or also as an aqueous solution, in Case of tert. Amines then preferred as their ammonium salts with acids Mineral acids, especially hydrochloric acid, respectively. When using multiple catalysts or dosing of course, partial amounts of the total amount of catalyst can also differ Dosage modes in different places or at different times be made. The total amount of catalysts used is between 0.001 to 10 mol% based on moles of bisphenols used, preferably 0.01 to 8 mol%, particularly preferably 0.05 to 5 mol%.

After entering the phosgene, it can be advantageous for a certain time the organic phase and the aqueous Mix phase before branching if necessary, if this is not dosed together with the bisphenolate, chain terminator and catalyst are added. Such a post-reaction time can be beneficial after each dose. These stirring times insofar as they are inserted, between 10 seconds and 60 minutes, preferably between 30 seconds and 40 minutes, especially preferably between 1 and 15 min.

The most fully reacted still traces of (<2 ppm) chlorocarbonic acid esters containing at least two-phase reaction mixture is allowed sit for phase separation. The aqueous alkaline phase becomes possibly back in whole or in part polycarbonate synthesis as aqueous Phase directed or fed to wastewater treatment, where Solvent- and catalyst portions are separated and recycled. In another After the organic impurities have been separated off, especially of solvents and polymer residues, and optionally after the adjustment of a certain pH, e.g. by adding sodium hydroxide solution, the salt is separated off, which e.g. the chlor-alkali electrolysis can be supplied while the aqueous Phase is optionally fed back to the synthesis.

The organic phase containing the polymer must now of all contaminations alkaline, ionic or catalytic Kind of be cleaned.

The organic phase also contains after one or more weaning operations, possibly supported by runs through settling tanks, stirred tanks, Coalescers or separators or combinations of these measures - where optionally water in each or some separation steps circumstances metered in using active or passive mixing elements can be - still Proportions of aqueous alkaline phase in fine droplets as well as the catalyst, usually a tert. Amine.

After this rough separation of the alkaline, watery Phase is the organic phase one or more times with dilute acids, mineral, carbon Hydroxycarbon and / or sulfonic acids washed. Aqueous are preferred Mineral acids in particular Hydrochloric acid, phosphorous acid and phosphoric acid or mixtures of these acids. The concentration of these acids should be in the range 0.001 to 50% by weight, preferably 0.01 to 5% by weight. % lie.

Furthermore, the organic phase washed repeatedly with deionized or distilled water. The Separation of the, optionally dispersed with parts of the aqueous phase, organic phase after the individual washing steps is done by means of Sedimentation tank, stirred tank, Coalescers or separators or combinations of these measures, the washing water between the washing steps if necessary be metered in using active or passive mixing elements can.

Between these washing steps or even after washing can optionally acids, preferably solved in the solvent which of the polymer solution underlying is to be admitted. Hydrogen chloride gas is preferred here and phosphoric acid or phosphorous acid used, which are optionally also used as mixtures can.

The purified polymer solution thus obtained should after the last separation process not more than 5% by weight, preferably less than 1% by weight, very particularly preferably less than 0.5% by weight Contain water.

According to the invention, this solution is now before the isolation step into a tank, which has a dwell time offers from 30 to 240 minutes. Then, preferably after one Filtration again isolates the polymer from the Solution. This happens, for example, by evaporating the solvent by means of temperature, Vacuum or a heated trailing gas. Other insulation methods are crystallization and precipitation.

Happens the concentration of polymer solution and possibly also the isolation of the polymer by distillation of the solvent, possibly by overheating and relaxation, one speaks of a "flash process" see also "thermal separation process", VCH publishing house 1988, P. 114; instead, a heated carrier gas is evaporated together with the one to be evaporated Solution sprayed, speaks one describes by way of example of "spray evaporation / spray drying" in Vauck, "Basic Operations chemical process engineering ", German publisher for Grundstoffindustrie 2000, 11th edition, p. 690. All these processes are described in the patent literature and in textbooks and the expert common.

When removing the solvent by temperature (distilling off) or the technically more effective Flash method receives highly concentrated polymer melts. With the known flash method become polyrier solutions repeated under slight overpressure heated to temperatures above the boiling point under normal pressure and this, regarding of normal pressure, overheated Solutions then in a vessel with a lower one Pressure, e.g. Normal pressure, relaxed. It can be an advantage the levels of concentration, or in other words, the temperature levels of overheating get too big but rather a two- to four-stage process choose.

From the highly concentrated polymer melts thus obtained, the residues of the solvent can either be obtained directly from the melt using evaporation extruders (BE-A 866 991, EP-A 0 411 510 . US-A 4 980 105 . DE-A 33 32 065 ), Thin film evaporators ( EP-A 0 267 025 ), Falling film evaporators, strand evaporators or by friction compaction ( EP-A 0 460 450 ), optionally also with the addition of an entrainer such as nitrogen or carbon dioxide or using a vacuum ( EP-A 0 039 96 . EP-A 0 256 003 . US-A 4,423,207 ) can be removed, alternatively by subsequent crystallization ( DE-A 34 29 960 ) and heating the residues of the solvent in the solid phase ( US-A 3,986,269 . DE-A 20 53 876 ).

Granules are obtained, if possible, by direct Spinning the melt and subsequent granulation or by using discharge extruders from those in the air or below Liquid, mostly water, is spun off. If extruders are used, it can one of the melt, before this extruder, optionally using from static mixers or through side extruders in extruders, additives enforce.

When sprayed, the polymer solution is optionally after heating, either sprayed into a vacuum vessel or by means of a nozzle a heated carrier gas, e.g. Nitrogen, argon or water vapor in a vessel with normal pressure atomized. In both cases receives one in dependence from the concentration of the polymer solution powder (diluted) or Flakes (concentrated) of the polymer from which, if necessary, also the last remnants of the solvent must be removed as above. Subsequently can by means of a compounding extruder and subsequent spinning Granules can be obtained. Here too, additives, as described above, in the periphery or the extruder itself. often must be before extrusion due to the low bulk density of the powder and flakes a compacting step for the polymer powder can be used.

From the washed and possibly still concentrated solution of the polycarbonate can by adding a non-solvent for polycarbonate the polymer is largely precipitated in crystalline form. Here it is advantageously only add a small amount of the non-solvent and if necessary also waiting times between batch additions of non-solvents appeal. It can also be advantageous to use different non-solvents. use as a precipitant find e.g. Hydrocarbons, especially heptane, i-octane, Cyclohexane and alcohols such as methanol, ethanol, i-propanol.

The precipitation is usually the polymer solution slowly a precipitant added, mostly alcohols like methanol, ethanol, i-propanol, but also cyclohexane or acetone used.

The materials thus obtained are like spray evaporation described processed into granules and optionally additive.

According to other processes, precipitation and crystallization products or amorphously solidified products in fine-grained form are crystallized by passing vapors of one or more non-solvents for polycarbonate, with simultaneous heating below the glass transition temperature, and further higher molecular weights condensed. If these are oligomers, possibly with different end groups (phenolic and chain terminators), one speaks of solid phase condensation.

The addition of additives serves the renewal the useful life or the color (stabilizers), the simplification processing (e.g. demoulders, flow aids, antistatic agents) or the adaptation of the polymer properties to certain loads (Impact modifiers, like rubbers; Flame retardants, colorants, glass fibers).

These additives can be used individually or in any Mixtures or several different mixtures of the polymer melt be added directly during the isolation of the polymer or but after melting the granulate in a so-called compounding step. You can the additives or their mixtures as a solid, that is be added to the polymer melt as a powder or as a melt. A Another type of dosage is the use of masterbatches or Mixtures of masterbatches of additives or additive mixtures.

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

Suitable antioxidants or thermal stabilizers are, for example:
Alkylated monophenols
Alkylthiomethylphenols
Hydroquinones and alkylated hydroquinones
tocopherols
Hydroxylated thiodiphenyl ether
alkylidene
O, N and S benzyl compounds
Hydroxybenzylated malonates,
Aromatic hydroxybenzyl compounds,
triazine
Acylaminophenols
Esters of β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid
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 acid,
Suitable thiosynergists
Secondary antioxidants, phosphites and phosphonites
Benzofuranones and Indolinones

Organic phosphites are preferred, Phosphonates and phosphines, mostly those in which the organic Leftovers completely or partly from optionally substituted aromatic radicals consist.

As a complexing agent for heavy metals and to neutralize traces of alkali, o / m are phosphoric acids, whole or partially esterified phosphates or phosphites

Suitable as light stabilizers (UV absorbers)
2- (2'-Hydroxyphenyl) benzotriazoles,
2-Hydroxybenzophenones,
Esters of substituted and unsubstituted benzoic acids,
Acrylates.
Sterically hindered amines. oxamide,
2.8. 2- (2-Hydroxyphenyl) -1,3,5-triazines,
substituted benzotriazoles are preferred.

Polypropylene glycols alone or in Combination with e.g. Sulfones or sulfonamides as stabilizers can against the injury used by gamma rays.

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

Processing aids such as Mold release agents, mostly derivatives of long-chain fatty acids, added become. Preferred are e.g. Pentaerythritol tetrastearate and glycerol monostearate. she alone or in a mixture, preferably in an amount of 0.02 up to 1 wt .-%, based on the mass of the composition used.

Suitable flame retardant additives are phosphate esters, i.e. Triphenyl phosphate, resorcinol diphosphate, bromine-containing compounds, such as brominated phosphoric acid esters, brominated oligocarbonates and polycarbonates, and preferably fluorinated salts organic sulfonic acids.

Suitable impact modifiers are butadiene rubber with grafted styrene acrylonitrile or methyl methacrylate, ethylene-propylene rubbers with grafted on maleic anhydride, Ethyl and butyl acrylate rubbers with grafted methyl methacrylate or styrene-acrylonitrile, interpenetrating siloxane and acrylate networks with grafted methyl methacrylate or styrene acrylonitrile.

Furthermore, colorants, such as organic Dyes or pigments or inorganic pigments, IR absorbers, individually, in a mixture or in combination with stabilizers, Glass fibers, glass (hollow) spheres, inorganic fillers can be added.

Polymer melts, produced by isolating the polymer or by compounding, are spun through a nozzle head in the form of a strand, cooled with gas, for example air or nitrogen, or a cooling liquid, usually water, and the solidified strands in commercially available granulators with cutting edges, for example on a per se rotating roller are granulated in air, under protective gas such as nitrogen or argon or under water. Depending on the device design, columnar graes are formed nulates with a round or elliptical cross section and a rough or smooth surface. The cut edges can be smooth or have a glass-like break with broken cut edges or residues remaining on the cut edges. It is desirable to have granules that are shaped as uniformly as possible, with as little protrusion remaining on the cut edges as possible. Furthermore, the proportion of dust in the granules should be kept as low as possible, preferably below 100 mg / kg granules. The diameter of the granules should be between 0.5 mm and 10 mm, preferably between 1-8 mm, particularly preferably 3-6 mm. While the length of the granules should be between 1-10 mm, preferably between 2-8 mm and the weight between 10-50 mg, preferably between 15-30 mg. Preference is given to a granulate whose ratio of diameter, in the case of an elliptical cross section of the mean diameter, to the length is 0.8 to 1.2, particularly preferably one with the ratio of ∼1. These parameters are subject to size distributions, preference is given to distributions which are as narrow as possible, that is to say granules which are dimensioned as uniformly as possible.

Cooling, spinning, granulation and the subsequent one Transportation or promotion the granulate with gas or liquid, and the subsequent one Storage, if necessary after a mixing or homogenization process to be designed so that as possible despite that possibly existing static charge no impurities on the Polymer, strand or granulate surface are applied, such as for example dust, machine abrasion, aerosol-like lubricants and other liquids as well as salts from possibly used water baths or cooling.

The subject of the present application are also the polycarbonates as used in the process according to the invention are obtained and their use for the production of extrudates and moldings, especially those for use in the transparent area, quite especially in the field of optical applications such as Sheets, multi-skin sheets, Glazing, lenses, lamp covers or optical data storage, such as audio CD, CD-R (W), DVD, DVD-R (W), mini discs in their various only readable or writable once, if necessary repeatable embodiments.

The extrudates and moldings the polymer of the invention are also the subject of the present application.

• 1. Sicherheitsscheiben, die bekanntlich in vielen Bereichen von Gebäuden, Fahrzeugen und Flugzeugen erforderlich sind, sowie als Schilde von Helmen.
• 2. Folien.
• 3. Blaskörper (s.a. US-A 2 964 794 ), beispielsweise 1 bis 5 Gallon Wasserflaschen.
• 4. Lichtdurchlässige Platten, wie Massivplatten oder insbesondere Hohlkammerplatten, beispielsweise zum Abdecken von Gebäuden wie Bahnhöfen, Gewächshäusern und Beleuchtungsanlagen.
• 5. Optische Datenspeicher, wie Audio CD's, CD-R(W)'s, DCD's, DVD-R(W)'s, Minidiscs und den Folgeentwicklungen.
• 6. Ampelgehäuse oder Verkehrsschilder.
• 7. Schaumstoffe mit offener oder geschlossener gegebenenfalls bedruckbarer Oberfläche.
• 8. Fäden und Drähte (s.a. DE-A 11 37 167 ).
• 9. Lichttechnische Anwendungen, gegebenenfalls unter Verwendung von Glasfasern für Anwendungen im transluzenten Bereich.
• 10. Transluzente Einstellungen mit einem Gehalt an Bariumsulfat und oder Titandioxid und oder Zirkoniumoxid bzw. organischen polymeren Acrylatkautschuken ( EP-A 0 634 445 , EP-A 0 269 324 ) zur Herstellung von lichtdurchlässigen und lichtstreuenden Formteilen.
• 11. Präzisionsspritzgussteile, wie Halterungen, z.B. Linsenhalterungen; hier werden gegebenenfalls Polycarbonate mit Glasfasern und einem gegebenenfalls zusätzlichen Gehalt von 1–10 Gew.-% Molybdändisulfid (bez. auf die gesamte Formmasse) verwendet.
• 12. optische Geräteteile, insbesondere Linsen für Foto- und Filmkameras ( DE-A 27 01 173 ).
• 13. Lichtübertragungsträger, insbesondere Lichtleiterkabel ( EP-A 0 089 801 ) und Beleuchtungsleisten.
• 14. Elektroisolierstoffe für elektrische Leiter und für Steckergehäuse und Steckverbinder sowie Kondensatoren.
• 15. Mobiltelefongehäuse.
• 16. Network interface devices.
• 17. Trägermaterialien für organische Fotoleiter.
• 18. Leuchten, Scheinwerferlampen, Streulichtscheiben oder innere Linsen.
• 19. Medizinische Anwendungen wie Oxygenatoren, Dialysatoren.
• 20. Lebensmittelanwendungen, wie Flaschen, Geschirr und Schokoladenformen.
• 21. Anwendungen im Automobilbereich, wie Verglasungen oder in Form von Blends mit ABS als Stoßfänger.
• 22. Sportartikel wie Slalomstangen, Skischuhschnallen.
• 23. Haushaltsartikel, wie Küchenspülen, Waschbecken, Briefkästen.
• 24. Gehäuse, wie Elektroverteilerkästen.
• 25. Gehäuse für elektrische Geräte wie Zahnbürsten, Föne, Kaffeemaschinen, Werkzeugmaschinen, wie Bohr-, Fräs-, Hobelmaschinen und Sägen.
• 26. Waschmaschinen-Bullaugen.
• 27. Schutzbrillen, Sonnenbrillen, Korrekturbrillen bzw. deren Linsen.
• 28. Lampenabdeckungen.
• 29. Verpackungsfolien.
• 30. Chip-Boxen, Chipträger, Boxen für Si-Wafer.
• 31. Sonstige Anwendungen wie Stallmasttüren oder Tierkäfige.

Further applications are, for example, but without restricting the subject matter of the present invention:

• 1. Safety panes, which are known to be required in many areas of buildings, vehicles and aircraft, and as shields for helmets.
• 2. Slides.
• 3. Bladder (see also US-A 2 964 794 ), for example 1 to 5 gallon water bottles.
• 4. Translucent panels, such as solid panels or in particular hollow chamber panels, for example for covering buildings such as train stations, greenhouses and lighting systems.
• 5. Optical data storage devices, such as audio CDs, CD-R (W) 's, DCD's, DVD-R (W)' s, mini discs and the subsequent developments.
• 6. Traffic light housing or traffic signs.
• 7. Foams with an open or closed, possibly printable surface.
• 8. Threads and wires (see also DE-A 11 37 167 ).
• 9. Lighting applications, optionally using glass fibers for applications in the translucent area.
• 10. Translucent settings containing barium sulfate and or titanium dioxide and or zirconium oxide or organic polymeric acrylate rubbers ( EP-A 0 634 445 . EP-A 0 269 324 ) for the production of translucent and light-scattering molded parts.
• 11. Precision injection molded parts, such as holders, for example lens holders; polycarbonates with glass fibers and an additional content of 1-10% by weight of molybdenum disulfide (based on the total molding composition) are optionally used here.
• 12. Optical device parts, in particular lenses for photo and film cameras ( DE-A 27 01 173 ).
• 13. Light transmission carrier, in particular optical fiber cable ( EP-A 0 089 801 ) and lighting strips.
• 14. Electrical insulating materials for electrical conductors and for connector housings and connectors as well as capacitors.
• 15. Mobile phone housing.
• 16. Network interface devices.
• 17. Carrier materials for organic photoconductors.
• 18. Lights, headlamp bulbs, lens flares or inner lenses.
• 19. Medical applications such as oxygenators, dialyzers.
• 20. Food applications, such as bottles, dishes and chocolate molds.
• 21. Applications in the automotive sector, such as glazing or in the form of blends with ABS as a bumper.
• 22. Sporting goods such as slalom poles, ski shoe buckles.
• 23. Household items, such as kitchen sinks, sinks, letter boxes.
• 24. Housings, such as electrical distribution boxes.
• 25. Housings for electrical devices such as toothbrushes, hair dryers, coffee machines, machine tools such as drilling, milling, planing machines and saws.
• 26. Washing machine portholes.
• 27. Protective glasses, sunglasses, corrective glasses or their lenses.
• 28. Lamp covers.
• 29. Packaging films.
• 30. Chip boxes, chip carriers, boxes for Si wafers.
• 31. Other applications such as stable mast doors or animal cages.

The following example is intended to illustrate the invention illustrate, but without restricting them.

Examples

Comparative Example:

In a production line with one Throughput of St polycarbonate is the filtration of the washed Polycarbonate operated with 200μ bag filters before evaporation, which have a standing time of approx. 2 days.

Example:

The plant of the comparative example is supplied with a retention tank with an average retention time of washed polycarbonate solution equipped of 150 minutes.

The dwell boiler is located in front of the filtration station.

Although the filter fineness is 0.6 was increased by increased the service life of the filter is two months. Within a 10 t were re-crystallized / crystallized in the residence time boiler Polycarbonate and in addition approx. 10 t of water separated.

Claims (4)

Process for the production of polycarbonates according to the phase interface process, characterized in that the polycarbonate solution wash is followed by a tank for the washed polycarbonate solution with a residence time of 30 to 240 minutes. Polycarbonate available according to the method of claim 1. Use of polycarboant according to claim 2 for the production of moldings and extrudates. Extrudates and molded articles containing polycarbonate according to claim Second