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
  • C08G64/30—General preparatory processes using carbonates
• • 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
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/78—Preparation processes
  • C08G63/785—Preparation processes characterised by the apparatus used
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
  • B01D3/14—Fractional distillation or use of a fractionation or rectification column
  • B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
  • B01D3/148—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step in combination with at least one evaporator
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
• • 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
• • 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
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
  • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
  • C08G63/16—Dicarboxylic acids and dihydroxy compounds
  • C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
  • C08G63/19—Hydroxy compounds containing aromatic rings

Definitions

• the invention relates to a process for the preparation of vapors and condensates which are formed in the production of polycondensates from bisphenols or higher-value phenols by esterification and / or transesterification with alkyl and / or aryl esters of at least divalent organic or inorganic acids.
• the degradation and rearrangement products formed during the reaction contaminate the monomers and oligomers also contained in the vapors and make it impossible to return the monomers and oligomers unpurified to the polycondensation process, if they are not discolored, they do not meet the rheological and mechanical quality requirements should be generated.
• the decomposition products formed during the polycondensation such as phenols, alcohols and water, are so contaminated by the degradation and rearrangement products mentioned that they cannot be reused easily.
• a reuse of the phenols contained in the vapors is disturbed by the reaction products formed during thermal degradation. It is therefore the task of developing a process for the preparation of vapors and condensates, which are produced in the production of the above-mentioned polycondensates, by means of which it is possible, on the one hand, to recover the monomers carried along and those of the polycondensation again and, on the other hand, to present the cleavage products, especially the phenol, produced during the polycondensation in such a way that they can be used again for further reactions without the product quality deteriorating.
• a process has now been found for the preparation of vapors and condensates which arise in the production of polycondensates from bisphenols or higher-quality phenols by esterification or transesterification with alkyl or aryl esters of at least divalent organic or inorganic acids, in which the preparation is carried out in several, gradually connected condensers and / or distillation columns with connected condensers, the dew point and the pressure being set in each condenser so that the respective monomers, oligomers or degradation and rearrangement products are separated in the individual stages.
• This process enables recyclable materials to be returned to the process, is particularly economical and cost-effective, avoids environmental pollution caused by chemicals and uses the by-products that are inevitably generated to generate energy.
• This method can be applied particularly well to the regeneration of phenol-containing vapors and condensates and to the recovery of monomers, as used, for example, in the production of polycarbonates, polyarylates or in the melt-phase polycondensation of polymers and copolymers, such as polyethylene, polypropylene or Polybutylene terephthalate with diphenols and bisphenols or polyhydric phenols are produced by esterification or transesterification with alkyl or aryl esters of organic or inorganic, at least dibasic acids and / or the acids themselves.
• polycondensates are known as engineering plastics with excellent properties and special fields of application. They are produced either by interfacial polycondensation as in the case of the polycarbonate or by melt polycondensation in the direct polycondensation process from dicarboxylic acids or dialcohols or diphenols or by transesterification processes from the corresponding acid esters.
• aromatic dihydroxy compounds for example bis (4-hydroxyphenyl) alkanes, in particular bisphenol A
• diphenyl carbonate or terephthalic acid diphenolate in the presence of catalysts with the elimination of phenols, oligomerized and finally polymerized in several stages as the vacuum progresses .
• catalysts with the elimination of phenols, oligomerized and finally polymerized in several stages as the vacuum progresses .
• the international patent application WO 02/44244 describes a process by which polycarbonates are produced by reacting a monomeric carbonate component with at least one diphenol or dialcohol in the presence of a transesterification catalyst, the molten components being stirred with the transesterification catalyst and mixed in Produces product, which is polycondensed.
• the transesterification product is passed through a prereactor, at least one intermediate reactor and an end reactor, the reactors being connected in series and having an essentially horizontally driven shaft with stirring elements attached to it.
• the monomers diphenyl carbonate 1 and bisphenol A 2 introduced into the reactor 4 are reacted with one another in the presence of a catalyst 3, the cleavage products 5, especially phenol, being obtained in large quantities at the start of the reaction even at low temperature and high pressure.
• the resulting distillate is passed into the condenser 6, its temperature is kept above the dew point of the cleavage products and that of the monomers 1 and 2, for example at a temperature above 200 ° C. and at 400 mbar.
• the high-boiling products 7 of the side reactions, such as spiroidans and indanes, contained in the vapors 5 of the first stage can thus be separated off.
• the further vapors then pass through the rectification column 8, in which the lowest-boiling cleavage products are driven off overhead, but the monomers 1 and 2 are drawn off on different trays and returned to the first reaction stage 4.
• the low-boiling fission product 10 is deposited in a condenser 11 and fed to a collecting container 28.
• the condensates occurring in the condenser 29 during the compression 12 go into the collecting container 27.
• the amount of low-boiling cleavage products 15 is already lower.
• more stringent measures such as higher temperature and lower pressure as in stage 1 are necessary to drive the reaction or chain growth forward, for example 270 to 300 ° C. and 100 hPa - 10 hPa Due to the higher thermal load, the products from side reactions appear increasingly in the vapor gas stream 16, consequently the amount of these product species which is produced in the condenser 6 'is also greater than in the previous stage 4.
• the condensate 7 obtained in 6 1 goes into the collecting container 24.
• the amount of monomers 1, 2 in the cleavage products has become so small that a separation is no longer worthwhile and everything is deposited in the condenser 8 '. is before the lowest boiling vapors are compressed in the compressor 16.
• the vapors from the compression 16 deposited on the condenser 17 are combined with the stream 10 and fed to the collecting container 28.
• the condensate 9 is fed into the rectification 8 in order to increase the yield of monomers 1, 2 and cleavage products 10.
• the smallest amount of cleavage products 20 occurs in the third reaction section (reactor 19, fed with product 18 from reactor 14).
• the harshest measures such as the highest temperature and the lowest pressure, are necessary to drive the reaction or chain growth, for example 280 to 35O 0 C and 10 hPa to 0.1 hPa. Due to the strong thermal The products of the side reactions take up a large portion of the load in the vapor gas stream 20, consequently the amount which accumulates in the condenser 6 "is also considerably higher than in the previous stages. The condensate 7 obtained in 6" goes into the collecting container 24.
• the amount of monomers 1 and 2 in the cleavage products has become so small that a separation is no longer worthwhile and everything is therefore deposited in the condenser 8 ".
• the vapors from the compression 21 deposited on the condenser 22 are fed to the collecting container 26 as compressor condensate 22 Remaining of the condensate 9 'is decided after an analysis in the quality control (QC) whether it is still in the rectification ion 8 can be fed in to increase the yield of monomers 1 and 2 and cleavage products 10, or is fed to the collecting container 25 for separate treatment according to FIG. 2.
• the products collected in the collecting containers 24 to 28 are the result of a coarse fractionation or pre-fractionation by selective choice of the reaction and / or condensation conditions. They represent the first stage of an overall process that leads to optimal and economical use of the monomers and of cleavage products.
• the product from the collecting container 24 has a high concentration of by-products, such as, for example, trisphenols, polymeric isopropenylphenols, dihydroxyindanes, dihydroxyspirobisindanes, alkyldistilboestrols and polyhyroxyarylene only requires a little effort to obtain recyclable products such as the monomers or the cleavage product.
• a fraction of the monomers 1 and 2 is obtained on the lower trays, which after passing through a quality control (QC) either directly after purification by crystallization 41, 43 and / or zone melting process 42, 44 as pure monomer 1 and / or 2 first stage with reactor 4 are fed again.
• the bottom of stage 34 contains only high boilers that go to incineration 32.
• the product 35 escaping at the top of the column 34 is rich in low-boiling cleavage products and occurs in the middle part of the column 36, into which the main part of the cleavage product from the collection containers 27 and 28 is also introduced.
• the pure cleavage product 37 leaving overhead is obtained, which after condensation 39 via the reflux tank 40 and quality control (QC) is either fed back to the column 36 or is used as the end product 45 for further use, for example for the production of acid esters or bisphenol A with acetone .
• the recovered product 45 meets the quality criteria of a product from the monomer synthesis.
• the quality control (QC) decides whether the bottom product 38 remains, which it either reassigns to column 34 or to incineration 32 as waste.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Polyesters Or Polycarbonates (AREA)
• Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
• Closing And Opening Devices For Wings, And Checks For Wings (AREA)

Priority Applications (4)

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Publications (1)

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Cited By (2)

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Citations (8)

Family Cites Families (13)

• 2005
  • 2005-04-15 DE DE102005017427A patent/DE102005017427A1/de not_active Withdrawn
• 2006
  • 2006-02-27 JP JP2008505746A patent/JP2008535980A/ja not_active Withdrawn
  • 2006-02-27 WO PCT/EP2006/001772 patent/WO2006108469A1/de not_active Ceased
  • 2006-02-27 CN CNA2006800126037A patent/CN101160341A/zh active Pending
  • 2006-02-27 US US11/918,636 patent/US20090114523A1/en not_active Abandoned
  • 2006-02-27 KR KR1020077026506A patent/KR20080015406A/ko not_active Withdrawn
  • 2006-02-27 EP EP06707287A patent/EP1869102A1/de not_active Withdrawn
• 2008
  • 2008-11-11 US US12/268,516 patent/US8029079B2/en active Active

Patent Citations (8)

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