Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
  • C07C37/11—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by reactions increasing the number of carbon atoms
  • C07C37/20—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by reactions increasing the number of carbon atoms using aldehydes or ketones
• • 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
  • C08G64/26—General preparatory processes using halocarbonates
  • C08G64/28—General preparatory processes using halocarbonates 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
  • C08G64/20—General preparatory processes
  • C08G64/30—General preparatory processes using carbonates
  • C08G64/307—General preparatory processes using carbonates and phenols

Definitions

• the present application relates to a process for the preparation of bisphenol A, in which the mixture comprising phenol and acetone is brought to a temperature of 48 to 54 ° C.
• cocatalysts are ammoalkylthiols and pyridylalkylthiols, which are ionically bound to the catalyst, whereby the SH function can be protected and is only released to the catalyst during or after fixation.
• the cocatalyst can be covalently bound to the catalyst as alkyl or aryl thiol.
• a product mixture is formed which, in addition to unreacted phenol and optionally acetone, contains primarily BPA and water.
• typical by-products of the condensation reaction occur in small amounts, for example 2- (4-hydroxyphenyl) -2- (2-hydroxyphenyl) propane (o, p-BPA), substituted indanes, hydroxyphenyl indanols, hydroxyphenyl chromanes, spirobisin dane, substituted rndenols, substituted xanthenes and higher condensed compounds with three or more phenyl rings in the molecular backbone.
• self-condensation of the acetone and reaction with impurities in the raw materials can result in the formation of further secondary components such as anisole, mesityl oxide, mesitylene and diacetone alcohol.
• reaction is usually carried out in such a way that 100% conversion of the acetone is not achieved and 0.1 to 0.6% by weight of acetone are still present in the reactor outlet.
• a processing and purification method of BPA is carried out by separating BPA from the reaction mixture in the form of an approximately equimolar crystalline adduct with phenol by cooling the reaction mixture with crystallization of the BPA-phenol adduct in a suspension crystallization.
• the BPA-phenol adduct crystals are then separated from the liquid phase by a suitable apparatus for solid-liquid separation, such as rotary filters or centrifuges, and sent for further purification.
• Adduct crystals obtained in this way typically have a purity of> 99% by weight of BPA, based on the sum of BPA and the secondary components, with a phenol content of approximately 40% by weight.
• suitable solutions which typically contain one or more components from the group consisting of acetone, water, phenol, BPA and secondary components, the adduct crystals can be freed from impurities adhering to the surface.
• the liquid stream (mother liquor) obtained in the solid-liquid separation contains phenol, BPA, water formed in the reaction, unreacted acetone and is enriched in the secondary components typically obtained in the production of BPA.
• This mother liquor stream is usually returned to the reaction unit.
• water previously formed is removed by distillation, wherein any acetone still present is also removed from the mother liquor.
• the dewatered reaction stream thus obtained is supplemented by phenol, acetone and optionally cocatalyst and returned to the reaction unit.
• the phenol can also be added in whole or in part before dewatering.
• part or all of the circulating stream after the solid-liquid separation and before or after the separation of water and residual acetone can be passed through a rearrangement unit filled with an acidic ion exchanger.
• This unit is generally operated at higher temperatures than the reaction unit.
• this rearrangement unit under the prevailing conditions, some of the secondary components of the BPA production present in the recycle stream are isomerized to BPA, so that the overall yield of BPA can be increased.
• the resin can also be subjected to a thermal, acidic or basic catalyzed cleavage.
• the phenol released and, if appropriate, also isopropenylphenol can be separated off by distillation and returned to the reaction.
• the BPA-phenol adduct crystals obtained after the above-described suspension crystallization of the reaction solution and solid-liquid separation are passed on to further purification steps, with the separation of phenol and possibly a reduction in the concentration of secondary components being achieved.
• the phenol can also be removed from the BPA-phenol adduct crystals by means of a melting process.
• a bisphenol A melt is obtained which can be used without prior solidification for the production of polycarbonate by the transesterification process (melt polycarbonate).
• the bisphenol A melt can also by known Processes, such as, for example, after the test procedure or by desquamation, are solidified for sale or recycling. Furthermore, the melt can be dissolved in sodium hydroxide solution and used for the production of polycarbonate by the phase interface process. If appropriate, the phenol-free bisphenol A can be subjected to a purification step such as melt crystallization, distillation and / or recrystallization from phenol, water or an organic solvent such as toluene or mixtures of these substances before further processing.
• the object of the present invention was therefore to provide a process for the preparation of bisphenol A, in which the formation of isomers during the reaction is reduced, and a high purity of bisphenol A is achieved after the crystallization and filtration in the end product and thus the discharged amount from the cycle stream, the so-called BPA resin, can be kept low.
• the acidic ion exchanger is preferably used in step c) in combination with a cocatalyst.
• cocatalyst usually thiols that have at least one SH function.
• the cocatalyst can either be dissolved homogeneously in the reaction solution or, in the case of the acidic ion exchangers, can be fixed on the catalyst itself.
• Homogeneous cocatalysts are, for example, mercaptopropionic acid, hydrogen sulfide, alkyl sulfides such as ethyl sulfide and similar compounds.
• cocatalysts are aminoalkylthiols and pyridylalkylthiols which are ionically bound to the catalyst, where the SH function can be protected and is only released to the catalyst during or after fixation.
• the cocatalyst can be covalently bound to the catalyst as alkyl or aryl thiol.
• the starting temperature of the reaction is ultimately lowered to a temperature in the range from 48 to 54 ° C.
• the amount of BPA resin to be discharged in order to keep the content of by-products, the so-called isomers, in the reactor constant on one for performing the crystallization and maintain the purity of the final product at an acceptable level. Due to the lower discharge, less bisphenol resin is obtained as a residue. Thus the amount of BPA resin is a direct indication of the isomer formation in the reaction. By reducing the reactor inlet temperature, the amount of resin can be reduced by up to 50%, which represents great economic savings with the same product quality.
• the reaction is preferably carried out in such a way that a reactor temperature of 77 ° C. is not exceeded.
• Adiabatic reaction control is preferred. In practice, this usually leads to the highest temperature occurring at the outlet of the reactor. The reactor outlet temperature is then the highest temperature that occurs in the reactor.
• Adiabatic reaction control also includes a reaction control in which the reactor jacket is slightly heated from the outside in order to avoid crystallization in wall areas.
• the low temperature at the start of the reaction at which a high concentration of acetone is still present, in particular reduces the acetone's own condensation and the formation of chromanes, indanes and other by-products of bisphenol A production known to the person skilled in the art.
• the content of the so-called isomers of 100 g / l in the reaction mixture after the reaction should not be exceeded if possible.
• a content of the so-called isomers of 60 to 100 g / l is preferably set in the reaction mixture at the reactor outlet.
• the amount of the diverted mother liquor is therefore less than 6% by weight, based on the amount of bisphenol A produced, if all components contained in the substream except phenol are taken into account Partial stream to be discharged from the mother liquor can easily be determined by the expert using standard analysis methods.
• the amount of BPA resin ultimately obtained can be further reduced by measures known to the person skilled in the art, such as, for example, rearrangement and resin cleavage.
• a BPA in a purity of greater than 99.5% by weight of p, p-bisphenol A can be obtained by the process according to the invention can be produced without additional purification by primary crystallization being necessary.
• the bisphenol A produced by the process according to the invention can be reacted with phosgene by the phase interface process or with diaryl carbonates, preferably diphenyl carbonate, to polycarbonate by the melt process.
• a reactor loaded with 100 m 3 of phenol-moist acidic ion exchanger Lewatit SC104 is reacted from top to bottom with a reaction solution consisting of 4% by weight acetone, 6% by weight isomers, 7% by weight bisphenol A, 0.05% by weight.
• a reaction solution consisting of 4% by weight acetone, 6% by weight isomers, 7% by weight bisphenol A, 0.05% by weight.
• the reactor inlet temperature is adjusted to 52 ° C.
• the reactor outlet temperature is 75 ° C.

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

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• 2004
  • 2004-02-05 DE DE102004005724A patent/DE102004005724A1/de not_active Withdrawn
• 2005
  • 2005-01-22 JP JP2006551754A patent/JP4874125B2/ja not_active Expired - Fee Related
  • 2005-01-22 EP EP05706966A patent/EP1713752A1/de not_active Withdrawn
  • 2005-01-22 SG SG200902915-8A patent/SG152282A1/en unknown
  • 2005-01-22 CN CNB200580003589XA patent/CN100516011C/zh not_active Expired - Fee Related
  • 2005-01-22 KR KR1020067015809A patent/KR20060130169A/ko not_active Application Discontinuation
  • 2005-01-22 RU RU2006131515/04A patent/RU2402521C2/ru not_active IP Right Cessation
  • 2005-01-22 WO PCT/EP2005/000615 patent/WO2005075396A1/de active Application Filing
  • 2005-01-26 US US11/043,769 patent/US20050176918A1/en not_active Abandoned
  • 2005-02-04 TW TW094103488A patent/TW200536876A/zh unknown

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