EP1794208A1 - Procede de production d'un polycarbonate - Google Patents

Procede de production d'un polycarbonate

Info

Publication number
EP1794208A1
EP1794208A1 EP05784029A EP05784029A EP1794208A1 EP 1794208 A1 EP1794208 A1 EP 1794208A1 EP 05784029 A EP05784029 A EP 05784029A EP 05784029 A EP05784029 A EP 05784029A EP 1794208 A1 EP1794208 A1 EP 1794208A1
Authority
EP
European Patent Office
Prior art keywords
sodium hydroxide
hydroxide solution
ppm
polycarbonate
chlorate
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05784029A
Other languages
German (de)
English (en)
Inventor
Ulrich Blaschke
Stefan Westernacher
Wolfgang Ebert
Rainer Neumann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Covestro Deutschland AG
Original Assignee
Bayer MaterialScience AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bayer MaterialScience AG filed Critical Bayer MaterialScience AG
Publication of EP1794208A1 publication Critical patent/EP1794208A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G64/00—Macromolecular compounds obtained by reactions forming a carbonic ester link in the main chain of the macromolecule
    • C08G64/20—General preparatory processes
    • C08G64/22—General preparatory processes using carbonyl halides
    • C08G64/24—General preparatory processes using carbonyl halides and phenols
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G64/00—Macromolecular compounds obtained by reactions forming a carbonic ester link in the main chain of the macromolecule
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G64/00—Macromolecular compounds obtained by reactions forming a carbonic ester link in the main chain of the macromolecule
    • C08G64/04—Aromatic polycarbonates
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G64/00—Macromolecular compounds obtained by reactions forming a carbonic ester link in the main chain of the macromolecule
    • C08G64/20—General preparatory processes
    • C08G64/22—General preparatory processes using carbonyl halides

Definitions

  • the invention relates to a process for the production of polycarbonate by the phase boundary surface method.
  • Polycarbonate is prepared, inter alia, by the phase boundary surface process known from the prior art in which dihydroxydiarylalkanes (bisphenols) in the form of their alkali metal salts (bisphenolates) with phosgene in a heterogeneous phase in the presence of inorganic bases such as sodium hydroxide solution and an organic solvent the product polycarbonate is well soluble, be implemented. So there are two phases, an aqueous and an organic, before. After the reaction, the organic polycarbonate-containing phase is washed with an aqueous liquid to, inter alia, remove electrolytes, and then the washing liquid is separated.
  • dihydroxydiarylalkanes bisphenols
  • bisphenolates alkali metal salts
  • bisphenol A is generally dissolved or suspended in sodium hydroxide solution to form sodium bisphenolate.
  • the purity of the sodium hydroxide solution used to prepare the sodium bisphenolate solution is decisive for the purity of the polycarbonate produced therefrom.
  • DE 199 52 848 A for example, a process for the production of polycarbonate is described in which the Roche ⁇ set sodium hydroxide solution has a low content of certain metals and the water used has VE quality.
  • the object of the present invention is therefore to provide a process for the preparation of polycarbonate by the interfacial process, in which the quality of the polycarbonate, in particular with respect to its color, is not impaired.
  • the invention accordingly provides a process for the production of polycarbonate by the interfacial process, comprising at least the following steps:
  • step (b) condensation of the oligocarbonates prepared according to step (a) in the presence of at least one catalyst
  • step (c) separating off the polycarbonate-containing organic phase obtained according to step (b),
  • a sodium hydroxide solution which contains a maximum of 30 ppm, preferably not more than 10 ppm, sodium chlorate, based on 100 wt.% Sodium hydroxide.
  • the invention further provides a process for preparing an aqueous sodium hydroxide solution of at least one dihydroxydiarylalkane by reacting a dihydroxydiarylalkane with an aqueous sodium hydroxide solution, the dihydroxydiarylalkane being present as solid and / or melt.
  • This process is characterized in that the sodium hydroxide solution contains not more than 30 ppm, preferably not more than 10 ppm, of sodium chlorate, based on 100% by weight of sodium hydroxide.
  • the sodium hydroxide solution used in the process according to the invention generally contains sodium chlorate as an impurity, so that the content of sodium chlorate is> 0 ppm, preferably> 0.1 ppm (based on 100% by weight of sodium hydroxide).
  • an aqueous sodium hydroxide solution of a disodium salt of at least one dihydroxydiarylalkane is also understood as meaning an aqueous sodium hydroxide suspension of the dihydroyxdiarylalkane or its disodium salt.
  • the preparation of polycarbonate according to the invention comprising the steps (a) to (c), and the inventive preparation of an aqueous sodium hydroxide solution of at least one dihydroxydiarylalkans is preferably carried out under inert conditions.
  • inert conditions are understood as meaning an oxygen content of not more than 20 ppb in the sodium hydroxide solution and any DI water used working under the greatest possible exclusion of oxygen.
  • Working under exclusion of oxygen is preferably carried out as described in DE 199 43 640 A and DE 198 59 690 A.
  • dihydroxydiarylalkane as melt is understood to mean both the direct use of the melt from the preparation of the dihydroxydiarylalkane without prior solidification and also the indirect use of a remelted dihydroxydiarylalkane after solidification, for example in the form of prills or flakes.
  • the interfacial process for producing polycarbonate comprising steps (a) to (c) is well known in the art.
  • the process and usable therein solvents, catalysts, chain terminators and branching agents and molecular weights of the polycarbonates are described for example in EP 411 433 A, EP 894 816 A or EP 1 352 925 A.
  • sodium hydroxide solution which contains not more than 30 ppm, preferably not more than 10 ppm, of sodium chlorate, based on 100% by weight of sodium hydroxide.
  • the use of such a caustic soda solution refers to all steps of the process in which caustic soda is used.
  • a sodium hydroxide solution containing a maximum of 30 ppm of sodium chlorate is used.
  • sodium hydroxide solution can be added which contains a maximum of 30 ppm sodium chlorate.
  • such a caustic soda may be used to dissolve a branching agent.
  • caustic soda with a maximum content of 30 ppm of sodium chlorate is likewise used.
  • the process according to the invention also comprises an embodiment in which initially a dilute solution of the dihydroxydiarylalkane is prepared from at least one dihydroxydiarylalkane and sodium hydroxide solution, which is subsequently brought to a higher concentration by addition of further dihydroxydiarylalkane.
  • the aqueous sodium hydroxide solution of the disodium salt is prepared by contacting the Dihydroxydi ⁇ arylalkans with sodium hydroxide solution.
  • the Dihydroxydiarylalkan be present in solid form, such as prills or flakes, or in the form of a melt.
  • the dihydroxydiarylalkane can first be brought into contact with water and then only with the sodium hydroxide solution. The production can take place both continuously and batchwise.
  • the concentration of the solution prepared according to the invention (the disodium salt) of a dihydroxydiarylalkane is from 3 to 25% by weight, preferably from 5 to 20% by weight, particularly preferably at 10 to 18 wt.%, Dihydroxydiarylalkan (or sum of Dihydroxydiarylalkane) based on the total Dihydroxydiarylalkanest.
  • the sodium hydroxide solution is preferably used in the process according to the invention as 2 to 55% by weight, particularly preferably as 5 to 35% by weight, solution.
  • the sodium hydroxide solution is present in a higher concentration, it is first diluted, preferably with demineralized water, hereinafter called demineralized water.
  • demineralized water is preferably desalted, degassed and, if appropriate, desiccated.
  • the demineralized water preferably has an electrical conductivity of not more than 0.2 ⁇ S / cm and a SiO 2 concentration of not more than 0.02 mg / kg (see also DE 19 952 848 A and DE 198 59 690 A).
  • the demineralized water, the sodium hydroxide solution and / or the dihydroxydiarylalkane solution are preferably filtered at least once, particularly preferably two to three times before the beginning of the reaction.
  • different filter types with pore sizes of, for example, 0.25 to 100 microns can be used.
  • the demineralized water is filtered twice, for example, using bag and / or candle filters with a pore size of 1 micron.
  • the dihydroxydiarylalkane solution is preferably first filtered once with polypropylene filters (pore size 50 ⁇ m), then twice with bag filters (5 ⁇ m and 1 ⁇ m pore size).
  • the content of other impurities in the sodium hydroxide solution is as low as possible.
  • oxidatively active substances such as perchlorate should be present at a maximum of 30 ppm, particularly preferably at most 10 ppm (based on 100% by weight of sodium hydroxide).
  • the content of sulfates, carbonates and chlorides in the sodium hydroxide should preferably be as low as possible.
  • a maximum of 120 ppm of chloride, a maximum of 80 ppm of sulfate and a maximum of 300 ppm of carbonate (based on 100% by weight of sodium hydroxide) are preferred here.
  • a sodium hydroxide solution with a maximum content of 30 ppm sodium chlorate can either be prepared directly with such a sodium chlorate content or indirectly, by first obtaining a sodium hydroxide solution with a higher content of sodium chlorate, the sodium chlorate content of which is subsequently reduced.
  • Processes for the production of caustic soda are well known.
  • a common method is the chloralkali electrolysis, wherein a distinction is made between the amalgam method, the membrane method and the diaphragm method. The latter have the advantage over the amalgam process that no mercury is used.
  • the content of metals in the resulting caustic soda is also lower in the membrane process.
  • a disadvantage of the membrane and diaphragm method is that the separation of the anode compartment and the cathode compartment is no longer completely guaranteed.
  • chlorate is formed by the contact of the chlorine with the sodium hydroxide solution.
  • the sodium hydroxide solution is prepared by means of an amalgam process.
  • a sodium hydroxide solution contains a maximum of 30 ppm sodium chlorate.
  • the caustic soda contains more than 30 ppm of sodium chlorate per 100% by weight of sodium hydroxide after its preparation, for example by means of the diaphragm-type or membrane process of chlor-alkali electrolysis
  • the content of sodium chlorate may e.g. be reduced by mixing with a sodium hydroxide solution with a lower content of sodium chlorate, for example produced by the amalgam process.
  • sodium hydroxide solution according to the Membranverfah ⁇ ren for example, 15 ppm sodium chlorate based on 100 wt.% Sodium hydroxide
  • sodium hydroxide solution by the diaphragm method for example, 45 ppm sodium chlorate bezo ⁇ gen to 100 wt.% Sodium hydroxide
  • sodium hydroxide solution having a sodium chlorate content of not more than 30 ppm, based on 100 wt.% Of sodium hydroxide for example, by mixing 50 parts of sodium hydroxide solution according to the Membranverfah ⁇ ren (for example, 15 ppm sodium chlorate based on 100 wt.% Sodium hydroxide) with 50 parts of sodium hydroxide solution by the diaphragm method (for example, 45 ppm sodium chlorate bezo ⁇ gen to 100 wt.% Sodium hydroxide)
  • the content of sodium chlorate in the sodium hydroxide solution can be lowered by lowering the content of sodium chlorate in the brine of the chloralkali electrolysis by chlorate decomposition in the brine circuit.
  • acidification of the brine for example with hydrochloric acid, the chlorate synpro- poses with the chloride to form chlorine.
  • Under the brine circuit is understood to mean the enrichment of the remaining brine with electrolysis with NaCl and their return to the electrolysis. In this case, an acidification for chlorate removal of the total amount of brine or even only parts of the brine can be done.
  • the content of sodium chlorate is deliberately lowered even in the sodium hydroxide solution itself, for example by treatment (addition) with inorganic reducing agents (for example sodium sulphite, sodium dithionite) or with organic reducing agents (For example, formaldehyde), by catalytic reduction with hydrogen or by removal by means of suitable ion exchangers or a combination of these methods.
  • inorganic reducing agents for example sodium sulphite, sodium dithionite
  • organic reducing agents for example, formaldehyde
  • the content of chlorate in the brine can be reduced by feeding from the brine circuit.
  • such brine derived from a membrane or diaphragm process may be used after any enrichment with NaCl in an amalgam process.
  • a polycarbonate In the production of polycarbonate using a sodium hydroxide solution with a maximum content of sodium chlorate of 30 ppm, a polycarbonate is formed, which has a lower intrinsic color and thus a compared to a polycarbonate, which was prepared with a sodium hydroxide solution with a higher sodium chlorate has a lower Yellowness Index (YI) as a measure of color.
  • YI Yellowness Index
  • Preferred starting materials for the preparation of the sodium hydroxide solution of at least one dihydroxyarylalkane are: dihydroxydiarylalkanes of the general formula HO-Z-OH, wherein Z is a divalent organic radical having from 6 to 30 carbon atoms and containing one or more aromatic groups.
  • Z is a divalent organic radical having from 6 to 30 carbon atoms and containing one or more aromatic groups.
  • Examples of such compounds are bisphenols belonging to the group of dihydroxydiphenyls, bis (hydroxyphenyl) alkanes, indanebisphenols, bis (hydroxyphenyl) ethers, bis (hydroxyphenyl) sulfones, bis (hydroxyphenyl) ketones and ⁇ , ⁇ '-bis (hydroxyphenyl) diisopropylbenzene - zole belong.
  • Particularly preferred bisphenols which belong to the abovementioned linking groups are 2,2-bis (4-hydroxy-phenyl) propane (bisphenol A (BPA)), tetraalkyl bisphenol A, 4,4- (meta-phenylenedi-isopropyl) diphenol (bisphenol M ), l, l-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and optionally mixtures thereof.
  • Particularly preferred copolycarbonates are those on the
  • a part, ie not more than 80 mol%, preferably 20 to 50 mol%, of the carbonate groups in the polycarbonates may be replaced by aromatic dicarboxylic acid ester groups.
  • Table 1 shows that with higher sodium chlorate content the absorption, i. Farbig ⁇ speed, the Natriumbisphenolatains increases.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Polyesters Or Polycarbonates (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

L'invention concerne un procédé de production d'un polycarbonate suivant le procédé d'interphase, caractérisé en ce qu'il comprend au moins les étapes suivantes : (a) réaction d'une solution aqueuse d'hydroxyde de sodium d'un sel disodique d'au moins un dihydroxydiarylalcane, avec le phosgène, en présence d'au moins un solvant organique, d'un agent de rupture de chaîne et, éventuellement, d'un agent ramifiant, (b) condensation de l'oligocarbonate produit à l'étape (a), en présence d'au moins un catalyseur, (c) séparation de la phase organique contenant le polycarbonate, obtenue à l'étape (b), et en ce qu'on utilise une solution d'hydroxyde de sodium renfermant au maximum 30 ppm, de préférence, au maximum 10 ppm de chlorate de sodium, pour 100 % en poids d'hydroxyde sodium.
EP05784029A 2004-09-22 2005-09-15 Procede de production d'un polycarbonate Withdrawn EP1794208A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102004045822A DE102004045822A1 (de) 2004-09-22 2004-09-22 Verfahren zur Herstellung von Polycarbonat
PCT/EP2005/009911 WO2006032401A1 (fr) 2004-09-22 2005-09-15 Procede de production d'un polycarbonate

Publications (1)

Publication Number Publication Date
EP1794208A1 true EP1794208A1 (fr) 2007-06-13

Family

ID=35405873

Family Applications (1)

Application Number Title Priority Date Filing Date
EP05784029A Withdrawn EP1794208A1 (fr) 2004-09-22 2005-09-15 Procede de production d'un polycarbonate

Country Status (8)

Country Link
US (1) US20060063906A1 (fr)
EP (1) EP1794208A1 (fr)
JP (1) JP2008513590A (fr)
KR (1) KR20070056106A (fr)
CN (1) CN101023118A (fr)
DE (1) DE102004045822A1 (fr)
RU (1) RU2007114944A (fr)
WO (1) WO2006032401A1 (fr)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011207918A (ja) * 2010-03-27 2011-10-20 Osaka Univ 電気化学を用いたポリマーの製造方法と生成物
CN104136489B (zh) * 2012-02-28 2016-08-24 沙特基础全球技术有限公司 制备具有增强的光学特性的聚碳酸酯的方法
WO2017021802A1 (fr) * 2015-07-31 2017-02-09 Sabic Global Technologies B.V. Polycarbonate à faible teneur en chlore et procédé pour sa fabrication et son analyse
US10544259B2 (en) 2015-08-31 2020-01-28 Sabic Global Technologies B.V. Polycarbonate with low chlorine content and a method of making and analyzing the same
EP3719051B1 (fr) * 2019-04-03 2021-11-03 Covestro Deutschland AG Procédé d'établissement du moment opportun d'ajout du polycarbonate de l'agent d'interruption de chaîne
CN113999382B (zh) * 2021-12-10 2023-07-11 万华化学集团股份有限公司 一种聚碳酸酯的制备方法

Family Cites Families (5)

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Publication number Priority date Publication date Assignee Title
US3017338A (en) * 1958-03-03 1962-01-16 Diamond Alkali Co Electrolytic process and apparatus
CN1170870C (zh) * 1998-12-23 2004-10-13 拜尔公司 双酚钠溶液的制备方法
DE19859690C1 (de) * 1998-12-23 2000-09-07 Bayer Ag Polycarbonate mit niedrigem Yellowness-Index
DE19952848A1 (de) * 1999-11-03 2001-05-10 Bayer Ag Verfahren zur Herstellung von Polycarbonaten
US6340736B1 (en) * 1999-11-29 2002-01-22 General Electric Company Method and apparatus for the production of polycarbonates with brine recycling

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2006032401A1 *

Also Published As

Publication number Publication date
US20060063906A1 (en) 2006-03-23
CN101023118A (zh) 2007-08-22
JP2008513590A (ja) 2008-05-01
WO2006032401A1 (fr) 2006-03-30
RU2007114944A (ru) 2008-10-27
DE102004045822A1 (de) 2006-04-06
KR20070056106A (ko) 2007-05-31

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