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

Definitions

• the present invention relates to a process for the preparation of aromatic polycarbonates according to the phase interface process from diphenols, which is characterized in that the catalysts used are N-ethylpyrrolidine, N-ethylpiperidine, N-ethylmorpholine, N-isopropylpiperidine or N-isopropylmorpholine in amounts of 0.01 mol% to 10 mol%, based on moles of diphenols used.
• the present invention also relates to the polycarbonates obtainable according to the process, which are notable for high light transmission and low yellowing tendency even after higher temperatures.
• the color stabilization of aromatic polycarbonates has hitherto preferably been carried out by adding additives, in particular phosphites (cf. DE-AS-1 128 653, DE-AS 2 140 207 and DE-OS 2 255 639), optionally in combination with other additives, for example with oxetane compounds (DE-OS 2 510 463).
• additives in particular phosphites (cf. DE-AS-1 128 653, DE-AS 2 140 207 and DE-OS 2 255 639), optionally in combination with other additives, for example with oxetane compounds (DE-OS 2 510 463).
• the method according to the invention uses a completely different principle, in that it uses the above-mentioned catalysts as catalysts in polycarbonate production by the two-phase interfacial polycondensation process (cf. DE-PS 959 497, DE-PS 1046311 and DE-PS 2 410 716) .
• N-methylpiperazine is used only with poor success as a catalyst for the production of polycarbonates. (Compare column 1, line 69 to column 2, line 27).
• polyamines including cyclic polyamines such as N, N-diethylpiperazine, are used for the production of polycarbonates.
• cyclic polyamines such as N, N-diethylpiperazine
• N-alkyl morpholines can be used as catalysts for the production of polycarbonates.
• special N-alkylmorpholines lead to polycarbonates with improved thermal stability compared to the catalysts also mentioned in these references, such as, for example, triethylamine.
• GB-PS 1072161 (see in particular page 2, lines 28 ff) describes the preparation of polycarbonates from di- ( ⁇ -trihalogen-a-hydroxyethoxy) alkanes, it being possible, inter alia, to use N-methylmorpholine as the tertiary base.
• N-methylmorpholine is not suitable as a catalyst according to the present invention.
• from 0.01 to 10 mol% preferably from 0.05 to 5 mol% and in particular from 0.05 to 2 mol%, based on moles of diphenols used, are used on the catalysts mentioned at the outset.
• N-ethylpiperidine is particularly suitable.
• the high molecular weight polycarbonates are produced according to the invention by the phase interface process.
• Diphenols in particular dihydroxydiarylalkanes or -cycloalkanes, for which, in addition to the unsubstituted dihydroxydiarylalkanes or -cycloalkanes, those which are substituted in the o-position to the phenolic hydroxyl groups are also suitable in the aqueous-alkaline phase, and one is used for the Added suitable polycarbonate solvent.
• phosgene is introduced at a temperature between 0 and 100 ° C and a pH between 9 and 14. The polycondensation takes place after the phosgenation.
• the catalysts suitable according to the invention can be added either before introducing phosgene or after introducing phosgene before polycondensation.
• the phosgene introduction times are between 1 and 60 minutes, the post-condensation between 2 and 120 minutes.
• the organic polymer solution is separated off and washed free of electrolytes with water.
• the polycarbonate can then be removed by evaporation of the solvent or by precipitation with non-solvents, e.g. Methanol or gasoline can be isolated.
• the polycarbonates produced by the process according to the invention can also be branched in a known manner.
• Suitable diphenols are, for example, hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, bis- (hydroxyphenyl) alkanes, such as, for example, C1-CS-alkylene- or C 2 -C 8 -alkylidene bisphenols, bis- (hydroxyphenyl) cycloalkanes, for example Cs-Cs-cycloalkylene or C 5 -C 6 -cycloalkylidene bisphenols, bis - (hydroxyphenyl) sulfides, ethers, ketones, sulfoxides or sulfones.
• ⁇ , ⁇ '- bis - (hydroxyphenyl) - diisopropylbenzenes and the corresponding nuclear alkylated or nuclear halogenated compounds Polycarbonates based on bis (4-hydroxyphenyl) propane-2,2 (bisphenol A), bis (4-hydroxy-3,5-dichlorophenyl) propane-2,2 (tetrachlorobisphenol A), bis are preferred - (4-hydroxy-3,5-dibromophenyl) propane - 2,2 (tetrabromobisphenol A), bis - (4-hydroxy-3,5-dimethylphenyl) propane - 2,2 (tetramethylbisphenol A), bis - ( 4-hydroxy-3-methyl-phenyl) -propane-2,2, bis - (4-hydroxyphenyl) -cyclohexane-1,1 (bisphenol Z) and based on trinuclear bisphenols such as a, a '- bis - (4 - hydroxy-phenyl) - diis
• the catalyst (see examples) is added to the resulting solution and the mixture is stirred for a further 15 minutes.
• a highly viscous solution is obtained, the viscosity of which is regulated by adding methylene chloride.
• the aqueous phase is separated off.
• the organic phase is washed free of salt and alkali with water.
• Polycarbonate is isolated from the washed-out solution and dried.
• the polycarbonate has a relative viscosity of 1.30-1.31, measured in a 0.5% solution of methylene chloride at 20 ° C. This corresponds approximately to a molecular weight of 34,000.
• the polycarbonate thus obtained is extruded and granulated.
• the reaction temperature is 72 ° C; the concentration of OH ions in the aqueous reaction phase is 0.08%.
• the average residence time is 1.4 minutes.
• the emulsion flowing out of the pump-around reactor is fed with additional sodium hydroxide solution to increase the OH concentration to 0.3 to 0.35%.
• the oligocarbonate is condensed in a reaction tube as described in DE-OS 1 920 302 or US Pat. No. 3,674,740.
• the average residence time is 4 minutes; the temperature 83 ° C.
• the aqueous reaction phase contains 0.32% OH ⁇ and 0.51% C0 3 ; There is no evidence of bisphenol.
• the polycarbonate solution is washed free of electrolytes, evaporated and isolated using an evaporation extruder.
• the polycarbonate has a relative viscosity of 1.30 to 1.31, measured in a 0.5% solution of methylene chloride at 20 ° C. This corresponds approximately to a molecular weight of 34,000.
• the polycarbonates were processed into test specimens.
• the test specimens are annealed at 140 ° C in a drying cabinet.
• the light transmission was measured according to DIN 5033 and DIN 4646 using a spectrophotometer.
• the drop in light transmission at 420 nm in the course of the heat treatment is a measure of the increasing discoloration of the test specimen.

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• 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)
• Compositions Of Macromolecular Compounds (AREA)

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• 1977
  • 1977-08-09 DE DE19772735775 patent/DE2735775A1/de not_active Withdrawn
• 1978
  • 1978-07-28 EP EP78100539A patent/EP0000753B1/de not_active Expired
  • 1978-07-28 DE DE7878100539T patent/DE2860295D1/de not_active Expired
  • 1978-08-07 IT IT50631/78A patent/IT1106867B/it active
  • 1978-08-08 SU SU782645703A patent/SU1020006A3/ru active
  • 1978-08-08 JP JP53095894A patent/JPS6053049B2/ja not_active Expired
  • 1978-08-08 BR BR7805075A patent/BR7805075A/pt unknown
• 1979
  • 1979-10-26 US US06/088,694 patent/US4346210A/en not_active Expired - Lifetime

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