CA2069721A1 - Process for isolating polycarbonates_with co2 under pressure - Google Patents
Process for isolating polycarbonates_with co2 under pressureInfo
- Publication number
- CA2069721A1 CA2069721A1 CA002069721A CA2069721A CA2069721A1 CA 2069721 A1 CA2069721 A1 CA 2069721A1 CA 002069721 A CA002069721 A CA 002069721A CA 2069721 A CA2069721 A CA 2069721A CA 2069721 A1 CA2069721 A1 CA 2069721A1
- Authority
- CA
- Canada
- Prior art keywords
- polycarbonate
- carbon dioxide
- solution
- methylene chloride
- temperatures
- 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.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 21
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 94
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 claims abstract description 76
- 239000004417 polycarbonate Substances 0.000 claims abstract description 52
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 51
- 229920000515 polycarbonate Polymers 0.000 claims abstract description 51
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 39
- 239000012530 fluid Substances 0.000 claims abstract description 26
- 239000000843 powder Substances 0.000 claims abstract description 12
- 238000002156 mixing Methods 0.000 claims abstract description 11
- 238000001879 gelation Methods 0.000 claims abstract description 7
- 239000013557 residual solvent Substances 0.000 claims abstract description 6
- 239000007789 gas Substances 0.000 claims abstract description 5
- 238000010924 continuous production Methods 0.000 claims abstract description 4
- 238000002955 isolation Methods 0.000 claims abstract description 4
- 239000007787 solid Substances 0.000 claims abstract description 4
- 239000002245 particle Substances 0.000 claims abstract description 3
- 238000001556 precipitation Methods 0.000 claims abstract 2
- 125000000325 methylidene group Chemical group [H]C([H])=* 0.000 abstract description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 abstract description 2
- 229940073584 methylene chloride Drugs 0.000 description 18
- 229920000642 polymer Polymers 0.000 description 9
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 229920001577 copolymer Polymers 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- UMPGNGRIGSEMTC-UHFFFAOYSA-N 4-[1-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexyl]phenol Chemical compound C1C(C)CC(C)(C)CC1(C=1C=CC(O)=CC=1)C1=CC=C(O)C=C1 UMPGNGRIGSEMTC-UHFFFAOYSA-N 0.000 description 1
- 229920004049 Makrolon® 2805 Polymers 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- VCCBEIPGXKNHFW-UHFFFAOYSA-N biphenyl-4,4'-diol Chemical group C1=CC(O)=CC=C1C1=CC=C(O)C=C1 VCCBEIPGXKNHFW-UHFFFAOYSA-N 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004737 colorimetric analysis Methods 0.000 description 1
- MCWXGJITAZMZEV-UHFFFAOYSA-N dimethoate Chemical compound CNC(=O)CSP(=S)(OC)OC MCWXGJITAZMZEV-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000004431 polycarbonate resin Substances 0.000 description 1
- 229920005668 polycarbonate resin Polymers 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000000079 presaturation Methods 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- HOWHQWFXSLOJEF-MGZLOUMQSA-N systemin Chemical compound NCCCC[C@H](N)C(=O)N[C@@H](CCSC)C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@@H]([C@@H](C)O)C(=O)N[C@@H](CC(O)=O)C(=O)OC(=O)[C@@H]1CCCN1C(=O)[C@H]1N(C(=O)[C@H](CC(O)=O)NC(=O)[C@H](CCCN=C(N)N)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CO)NC(=O)[C@H]2N(CCC2)C(=O)[C@H]2N(CCC2)C(=O)[C@H](CCCCN)NC(=O)[C@H](CO)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@@H](NC(=O)[C@H](C)N)C(C)C)CCC1 HOWHQWFXSLOJEF-MGZLOUMQSA-N 0.000 description 1
- 108010050014 systemin Proteins 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
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
- C08G64/40—Post-polymerisation treatment
- C08G64/403—Recovery of the polymer
Abstract
Mo-3738 LeA 28,369 A PROCESS FOR ISOLATING POLYCARBONATES
ABSTRACT OF THE DISCLOSURE
A continuous process for the isolation of polycarbonates from a solution of polycarbonate in methylene chloride at temperatures of 30 to 80°C is disclosed. The process which yields polycarbonate in powder form having residual solvent content of less than 5% by weight, is characterized in that it entails the following steps:
a) obtaining a solution of polycarbonate in methylene chloride containing 10 to 40 percent polycarbonate, said percent being relative to the total weight of the polycarbonate solution, b) mixing into said solution under pressures of 10 to 50 bar and at temperaturesof 30 to 50°C a fluid containing carbon dioxide resulting in a non-gelling polycarbonate/methylene/chloride/dioxide pressurized system, in which between 10 and 12 % CO2 are dissolved, c) mixing said pressurized system in a two-component nozzle with additional fluid containing carbon dioxide under a pressure of 50 to 300 bar and at temperatures of 40 to 150°C, to cause rapid precipitation of polycarbonate in the form of solid particles, the quantitative ratio of CO2 to solution being between 1.0 and 15, preferably between 2.5 and 8.0, f) separating methylene chloride and carbon dioxide gases in a compressor/condenser system.
The process is further characterized in that a time interval of at least 0.1 second separates step b) and step c), and in that the input of the fluid containing carbon dioxide is controlled to prevent gelation in step b) and in that the pressurized system is above the gelation range in step c).
Le A 28 369-Foreign Countries
ABSTRACT OF THE DISCLOSURE
A continuous process for the isolation of polycarbonates from a solution of polycarbonate in methylene chloride at temperatures of 30 to 80°C is disclosed. The process which yields polycarbonate in powder form having residual solvent content of less than 5% by weight, is characterized in that it entails the following steps:
a) obtaining a solution of polycarbonate in methylene chloride containing 10 to 40 percent polycarbonate, said percent being relative to the total weight of the polycarbonate solution, b) mixing into said solution under pressures of 10 to 50 bar and at temperaturesof 30 to 50°C a fluid containing carbon dioxide resulting in a non-gelling polycarbonate/methylene/chloride/dioxide pressurized system, in which between 10 and 12 % CO2 are dissolved, c) mixing said pressurized system in a two-component nozzle with additional fluid containing carbon dioxide under a pressure of 50 to 300 bar and at temperatures of 40 to 150°C, to cause rapid precipitation of polycarbonate in the form of solid particles, the quantitative ratio of CO2 to solution being between 1.0 and 15, preferably between 2.5 and 8.0, f) separating methylene chloride and carbon dioxide gases in a compressor/condenser system.
The process is further characterized in that a time interval of at least 0.1 second separates step b) and step c), and in that the input of the fluid containing carbon dioxide is controlled to prevent gelation in step b) and in that the pressurized system is above the gelation range in step c).
Le A 28 369-Foreign Countries
Description
20~972:~
~,,.
Mo-3738 LeA 28,369 A PROCESS FOR lSOLATENG POLYC RBONATES
Field of The Invention The invention concerns polycarbonate resins and in particular their manufacture.
Summar~ of the Invention A continuous process for the isolation of polycarbonates from a solution of polycarbonate in methylene chloride at temperatures of 30 to 80C is disclosed. The process which yields polycarbonate in powder form having residual solvent o content of less than 5% by weight, is characterized in that it entails the following st;eps:
a) obtaining a solution of polycarbonate in methylene chloride containing 10 to 40 percent polycarbona~e, said percent being relative to the total weight of the polycarbonate solution, b) mixinginto said solution under pressures of 10 to ~0 bar and at temperatures of 30 to 50C a fluid containing carbon dioxide resulting in a non-~elling polycarbonate/methylene chloride/c~rbon dioxide 20. pressurized systemin which ~tw~ lO and 12% 2 are dissolved, c) mixing said pressurized system in a two-component nozzle with additional fluid containing carbon dioxide under a pressure of 50 to ~ bar and at ~peratures of 40 to 150C, to cause rapid precipi~tion of polyca~onate in the form of solid ~rticles, thequantitative ratio ~2 to solu~ion being ~n I.O and 15, p~ferably be~en 2.5 and 8.n, f) separating methylene chloride and carbon dioxide gases in a compressor/condenser system.
The process is further characterized in that a time interval of at least 0.1 second separates step b) and step c), and in that the input of the fluid containing carbon dioxide is controlled to prevent gelation in step b) and in that the pressurized system is above the gelation range in step c).
Le A 28 369 - Foreign Countries 2~97~1 BACKGROUND nF THE INVENTION
German patent application P 40 40 855.8 (Le A 27 877) describes a process for isolating polymers from their solvents by addition of fluids containing carbon dioxide at temperatures of 30C to 280C and under pressures of 1 bar to 1~000 bar, characterized in that the concentration of the polymers in their solvents is between 5% by weight and 80% by weight and in that the fluid containing carbon dioxide consists of at least 50% by weight carbon dioxide.
Compared with other processes for isolating polymers from their solvents, as described for example in US 4,634,761, EP
334 314 A2, DE 3 840 293 A1,-JP O 116 830-A2 and the publication "Yamamoto Kojia et al.: Kagaku Kogaku Ronbunshu 15 (3), Vol. 1989, pages 673-6759 the process described in the lS 6erman patent application has the advantage that large quantities of solvent are removed quickly and easily without significant exposure of the product to heat.
It has now been found that the isolation process described in German patent application P 40 40 8~S.8 (Le A 27 877~ can be ~0 improved in regard to the production of polycarbonate in powder form.
DETAILED DE~CRIPTION OF THE INVENTION
Accordingly, the present invention relates to a continuous process for isolating polycarbonates frvm methylene chloride at temperatures of 30 to 80C, resulting in a polycarbonate product in the form of powder having residual solvent contents of less than 5% by weight. The process is characterized in that a) starting out from a solution of polycarbonate in methylene chloride which contains 10 to 40% by weight polycarbonate, based on the total weight of the polycarbonate solut;on, b) fluid containing carbon dioxide is first mixed in typically under pressures of 10 to SO bar and at temperatures of 30 to 50C, so that the resulting L~ A 28369-Foreign Counbies 2~97~
pressuri7ed polycarbonate/methylene chloride/carbon dioxide system does not gel and contains 10 to 12 % CO2 dissolved ~herein, c) the pressurized solution containing polycarbonate, me~hylene chlolide and fluid containing carbon dioxide is mixed in a two-component no~zle with more of the fluid containing carbon dioxide under a pressure of 50 to 300 bar, preferably 70 to 200 bar at temperatures of 40 to 150C, preferably 80 to 120C, to form a three-phase system in which the quantitative ratio of C2 to solution is finally between l.û and 15, and preferably bet~Yeen 2.5 and X.0, d) a holding time of at least 0.1 second ~eing established between step b) and step c) and e) the input of the fluid containing carbon dioxide generally being controlled via the thermal conditions so that polycarbonate does not gel in step b) and the polycarbonate/methylene chloride/carbon dioxide system is above the gelation range in step c) due to the adequate degree of super-saturation and polycarbonate rapidly precipitates from ~he three-phase sys2em in the form of solid particles, the control being effected by the thelmal condidons, namely pressure and temperature, and by the residence time, of which the pressure is the most crucial parameter, f) methylene chloride and carbon dioxide gases largely being separated in a compressor/condenser system and carbon dioxide being returned to ~e supercridcal fluid extraction process.
The polycarbonate/methylene chloride/carbon dioxide system does not gel if it is constantly kept at below the point of c~itical supersatura~on. It does not for example gel if the temperature is > 30C, the pIessure is < 40 bar or the CO2 content is < 8 % by weight. The more closely ~e system approaches critical supersatura~ion the shorter is the required residence time, such as for example a ma~Limum of 35 ~ùnutes at 48C and S0 bar.
Suitable fluids containing carbon-dioxide are fluids which contain at least 20 % by weight, preferably at least 50 % by weight and most preferably at least 80 % by weight, based on ~he total weight of the fluid, of pure carbon dioxide. Other gases are for example N2, CH4, inert gases or sulfor hexafluoride, it being possible to use Cl to C10 alcohols, ketones or n-alkanes as entraining agents. Other pre~erred fluids con~aining carbon dioxide are those which contain impurities of methylenechloride. At least 20 % by weight CO2 means 20 to 100 % by weight CO2, and ~e same applies in the case OI at least 50 % by weight and at least 80 % by weight.
Le A 28 369 - Foreign Counbies 2~72~
Suitable polycarbonates are any thermoplastic and aliphatic polycarbonates having molecular weight, solution viscosities, distribu~ons and unifo~nities in known ranges. The only important requirement is tha~ the polycarbonates to be used should 90e soluble in methylene chlonde at the temperatures applied. Preferred polycarbonates are aromatic polycarbonates based on diphenols, for example of the type desaibed in US-PSS 3,028,365, 2,999,835, 3,148,172, 3,275,601, 2,991,273, 3,271,367, 3,096,278, 2,970,13~ and 2,999,846 and in DF-OSS I 570 703, 2 063 050, 2 063 052, 2 211 095, 3 832 396 (Le A 26 344) and 3 833 953 ~Le A 26 397).
Particularly preferred polycarbonates are those containing at least S mol-%, based on the total quantity of diphenols used (= 100 mol-%)9 of the following diphenols:
~,,.
Mo-3738 LeA 28,369 A PROCESS FOR lSOLATENG POLYC RBONATES
Field of The Invention The invention concerns polycarbonate resins and in particular their manufacture.
Summar~ of the Invention A continuous process for the isolation of polycarbonates from a solution of polycarbonate in methylene chloride at temperatures of 30 to 80C is disclosed. The process which yields polycarbonate in powder form having residual solvent o content of less than 5% by weight, is characterized in that it entails the following st;eps:
a) obtaining a solution of polycarbonate in methylene chloride containing 10 to 40 percent polycarbona~e, said percent being relative to the total weight of the polycarbonate solution, b) mixinginto said solution under pressures of 10 to ~0 bar and at temperatures of 30 to 50C a fluid containing carbon dioxide resulting in a non-~elling polycarbonate/methylene chloride/c~rbon dioxide 20. pressurized systemin which ~tw~ lO and 12% 2 are dissolved, c) mixing said pressurized system in a two-component nozzle with additional fluid containing carbon dioxide under a pressure of 50 to ~ bar and at ~peratures of 40 to 150C, to cause rapid precipi~tion of polyca~onate in the form of solid ~rticles, thequantitative ratio ~2 to solu~ion being ~n I.O and 15, p~ferably be~en 2.5 and 8.n, f) separating methylene chloride and carbon dioxide gases in a compressor/condenser system.
The process is further characterized in that a time interval of at least 0.1 second separates step b) and step c), and in that the input of the fluid containing carbon dioxide is controlled to prevent gelation in step b) and in that the pressurized system is above the gelation range in step c).
Le A 28 369 - Foreign Countries 2~97~1 BACKGROUND nF THE INVENTION
German patent application P 40 40 855.8 (Le A 27 877) describes a process for isolating polymers from their solvents by addition of fluids containing carbon dioxide at temperatures of 30C to 280C and under pressures of 1 bar to 1~000 bar, characterized in that the concentration of the polymers in their solvents is between 5% by weight and 80% by weight and in that the fluid containing carbon dioxide consists of at least 50% by weight carbon dioxide.
Compared with other processes for isolating polymers from their solvents, as described for example in US 4,634,761, EP
334 314 A2, DE 3 840 293 A1,-JP O 116 830-A2 and the publication "Yamamoto Kojia et al.: Kagaku Kogaku Ronbunshu 15 (3), Vol. 1989, pages 673-6759 the process described in the lS 6erman patent application has the advantage that large quantities of solvent are removed quickly and easily without significant exposure of the product to heat.
It has now been found that the isolation process described in German patent application P 40 40 8~S.8 (Le A 27 877~ can be ~0 improved in regard to the production of polycarbonate in powder form.
DETAILED DE~CRIPTION OF THE INVENTION
Accordingly, the present invention relates to a continuous process for isolating polycarbonates frvm methylene chloride at temperatures of 30 to 80C, resulting in a polycarbonate product in the form of powder having residual solvent contents of less than 5% by weight. The process is characterized in that a) starting out from a solution of polycarbonate in methylene chloride which contains 10 to 40% by weight polycarbonate, based on the total weight of the polycarbonate solut;on, b) fluid containing carbon dioxide is first mixed in typically under pressures of 10 to SO bar and at temperatures of 30 to 50C, so that the resulting L~ A 28369-Foreign Counbies 2~97~
pressuri7ed polycarbonate/methylene chloride/carbon dioxide system does not gel and contains 10 to 12 % CO2 dissolved ~herein, c) the pressurized solution containing polycarbonate, me~hylene chlolide and fluid containing carbon dioxide is mixed in a two-component no~zle with more of the fluid containing carbon dioxide under a pressure of 50 to 300 bar, preferably 70 to 200 bar at temperatures of 40 to 150C, preferably 80 to 120C, to form a three-phase system in which the quantitative ratio of C2 to solution is finally between l.û and 15, and preferably bet~Yeen 2.5 and X.0, d) a holding time of at least 0.1 second ~eing established between step b) and step c) and e) the input of the fluid containing carbon dioxide generally being controlled via the thermal conditions so that polycarbonate does not gel in step b) and the polycarbonate/methylene chloride/carbon dioxide system is above the gelation range in step c) due to the adequate degree of super-saturation and polycarbonate rapidly precipitates from ~he three-phase sys2em in the form of solid particles, the control being effected by the thelmal condidons, namely pressure and temperature, and by the residence time, of which the pressure is the most crucial parameter, f) methylene chloride and carbon dioxide gases largely being separated in a compressor/condenser system and carbon dioxide being returned to ~e supercridcal fluid extraction process.
The polycarbonate/methylene chloride/carbon dioxide system does not gel if it is constantly kept at below the point of c~itical supersatura~on. It does not for example gel if the temperature is > 30C, the pIessure is < 40 bar or the CO2 content is < 8 % by weight. The more closely ~e system approaches critical supersatura~ion the shorter is the required residence time, such as for example a ma~Limum of 35 ~ùnutes at 48C and S0 bar.
Suitable fluids containing carbon-dioxide are fluids which contain at least 20 % by weight, preferably at least 50 % by weight and most preferably at least 80 % by weight, based on ~he total weight of the fluid, of pure carbon dioxide. Other gases are for example N2, CH4, inert gases or sulfor hexafluoride, it being possible to use Cl to C10 alcohols, ketones or n-alkanes as entraining agents. Other pre~erred fluids con~aining carbon dioxide are those which contain impurities of methylenechloride. At least 20 % by weight CO2 means 20 to 100 % by weight CO2, and ~e same applies in the case OI at least 50 % by weight and at least 80 % by weight.
Le A 28 369 - Foreign Counbies 2~72~
Suitable polycarbonates are any thermoplastic and aliphatic polycarbonates having molecular weight, solution viscosities, distribu~ons and unifo~nities in known ranges. The only important requirement is tha~ the polycarbonates to be used should 90e soluble in methylene chlonde at the temperatures applied. Preferred polycarbonates are aromatic polycarbonates based on diphenols, for example of the type desaibed in US-PSS 3,028,365, 2,999,835, 3,148,172, 3,275,601, 2,991,273, 3,271,367, 3,096,278, 2,970,13~ and 2,999,846 and in DF-OSS I 570 703, 2 063 050, 2 063 052, 2 211 095, 3 832 396 (Le A 26 344) and 3 833 953 ~Le A 26 397).
Particularly preferred polycarbonates are those containing at least S mol-%, based on the total quantity of diphenols used (= 100 mol-%)9 of the following diphenols:
4,4'-dihydroxydiphenyl, 2,2-bis-(4-hydroxyphenyl)-propane, 2-2-bis-~3,5-dimethyl-4-hydroxyphenyl)-propane and 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethyl cyclohexane. The polycarbonates may be copolymers or homopolymers and mixtures may also be used. The copolymers may be block copolymers or statistica1copolymers and may also be branched.
Polycarbonate solution in methylene chloride in parts by weight of 10 to 40 %
by weight are generally obtained in the production of polycarbonate by the two-phase boundary process. The polycarbonates to be isolated according to the invention are generally obtained in the abovemendoned concentrations in such methylene chloride solutions.
Other components which, together wi~ ~he c,arbon dioxide, ~orrn the flllid containing carbon dioxide may be any other components which do not damage the polycarbonate or the methylene chloride. Compon~nts which stabilize the polycarbonate against external influences (W, weathering, etc.) may optionally be used as these other components.
2 5 Two-component nozzles are used as the mixing elemen~ Preferred two-component nozzles are those which thoroughly n~ix the low-viscosity fluid containing carbon dioxide with the relatively high-viscosity methylene chloIide/fluid/polycarbonate system and which offer a holding time in the nozzle under favorable mixing conditions of at least l/30th of a second.
The preferred mixing conditions are provided by the nozzle geometry in such a manner that 1) the components are introduced tangentially into the mixing chamber of the nozzle, 2) the streams are oriented in such a manner that a ram jet mixing effect is achieved and 3) additional fittings, such as swirl plates, are providPd in the nozzle charnber.
Le A 28 369 - Foreign Countries 2~6972~
The precipitated polycarbonate is expanded toge~her with the me~ylene chloride and the fluid containing carbon dioxide in an expansion vessel. The arrangement of the nozzle and the expansion vessel may preferably be selected sothat the powder ~avels a distance equivalent to at leas~ 1/10~ of a second or for example 175 mm, ~fore being deposi~ed in the expansion vessel. The powder may then be further prooessed to gr~nules and may even be compa~ted.
The fluid is returned to the process Yia a oondenser/compressor sys~em. The fluid may ccnSain up to 20 % by weight, based ~n ~e to~al weight of ~he fluid, of me~hylene ohloride as impurity.
EXAMPLES
General procedure for the Examples:
700 g polycarbonate based on bisphenol A (Makrolon 2805) having a relative viscosity of 1.28, as measured for 5 9 polymer in 1,000 9 methylene chloride at 25C, are dissolYed in 4,300 9 methylene chloride. The polymer solution is accommodated in a 50 liter autoclave at 50C into which carbon dioxide is introduced with intensive stirring until a predetermined pressure has been established (Presaturation according to (b)). The solution is then combined with continued introduction of carbon dioxide in a conical mixing nozzle with a swirl plate and two feed pipes for m~re carbon dioxide and the polym~r solution taccording io (c)). The rate atwhich the polymer solution and the carbon dioxide are fed to the nozzle is adjus~d (according to (d)). The nozzle is follo~ by a 100 liter expansion vessel in which the precipitating polycarbonate is whirled around together with the methylene chloride and the carbon dioxide. Samples are taken and analyzed at minute intervals during the distraction process. The following process parameters are varied:
- initial pressure in the storage vessel - feed rate of the polymer solution - feed rate and quantity of the carbon dioxide - pressure of the carbon dioxide at the nozzle.
The back pressure at the nozzle, the residual methylene chloride content and the morphology and apparent density of the powder are analyzed.
Le A 28 369 - Foreign Countries 2~72~
~e~
The initial pressure9 i.e. the pressure in step (b), is 20 bar Feed rate 17.6 ml/min.
Quantity of C02 in nozzle, based on the total quantity of polymer solutian: 500%
Carbon dioxide introduced under a pressure of 130 bar at a temperature of 110C.
Result: nozzle back pressure 90 bar, residual methylene chloride content of all samples under 1%t completely amorphous powder in every case (characteri~ed by differential scanning colorimetry), apparent density 0.10 g/cm .
e 2 The initial pressure, i.e. the pressure in step (b), is 30 bar Feed rate of polymer solution: 31.4 ml/min.
Quantity of C02 in nozzle: 19.5 kg/hour Temperature of C02 before nozzle: 105C
Temperature of PC solution: 25C before the nozzle The expansion vessel was preheated to 70C and kept at that temperature. Pressure of the C02 before the noz~le: 90 bar.
Result: nozzle back pressure 85 bar, apparent density 0.07 g/cm , fine-particle amorphous powder, residual solvent content under- 1%. The powder was very free-flowing and did not agglomerate or cake.
Comparison Example No initial pressure, otherwise as in Example 1. The test had to be terminated after a few minutes because the no7zle was blocked. The powder nad an apparent density of 0.015 g/cc and had a low residual solvent content (~2%).
Le A 28 369 - Foreign Countries
Polycarbonate solution in methylene chloride in parts by weight of 10 to 40 %
by weight are generally obtained in the production of polycarbonate by the two-phase boundary process. The polycarbonates to be isolated according to the invention are generally obtained in the abovemendoned concentrations in such methylene chloride solutions.
Other components which, together wi~ ~he c,arbon dioxide, ~orrn the flllid containing carbon dioxide may be any other components which do not damage the polycarbonate or the methylene chloride. Compon~nts which stabilize the polycarbonate against external influences (W, weathering, etc.) may optionally be used as these other components.
2 5 Two-component nozzles are used as the mixing elemen~ Preferred two-component nozzles are those which thoroughly n~ix the low-viscosity fluid containing carbon dioxide with the relatively high-viscosity methylene chloIide/fluid/polycarbonate system and which offer a holding time in the nozzle under favorable mixing conditions of at least l/30th of a second.
The preferred mixing conditions are provided by the nozzle geometry in such a manner that 1) the components are introduced tangentially into the mixing chamber of the nozzle, 2) the streams are oriented in such a manner that a ram jet mixing effect is achieved and 3) additional fittings, such as swirl plates, are providPd in the nozzle charnber.
Le A 28 369 - Foreign Countries 2~6972~
The precipitated polycarbonate is expanded toge~her with the me~ylene chloride and the fluid containing carbon dioxide in an expansion vessel. The arrangement of the nozzle and the expansion vessel may preferably be selected sothat the powder ~avels a distance equivalent to at leas~ 1/10~ of a second or for example 175 mm, ~fore being deposi~ed in the expansion vessel. The powder may then be further prooessed to gr~nules and may even be compa~ted.
The fluid is returned to the process Yia a oondenser/compressor sys~em. The fluid may ccnSain up to 20 % by weight, based ~n ~e to~al weight of ~he fluid, of me~hylene ohloride as impurity.
EXAMPLES
General procedure for the Examples:
700 g polycarbonate based on bisphenol A (Makrolon 2805) having a relative viscosity of 1.28, as measured for 5 9 polymer in 1,000 9 methylene chloride at 25C, are dissolYed in 4,300 9 methylene chloride. The polymer solution is accommodated in a 50 liter autoclave at 50C into which carbon dioxide is introduced with intensive stirring until a predetermined pressure has been established (Presaturation according to (b)). The solution is then combined with continued introduction of carbon dioxide in a conical mixing nozzle with a swirl plate and two feed pipes for m~re carbon dioxide and the polym~r solution taccording io (c)). The rate atwhich the polymer solution and the carbon dioxide are fed to the nozzle is adjus~d (according to (d)). The nozzle is follo~ by a 100 liter expansion vessel in which the precipitating polycarbonate is whirled around together with the methylene chloride and the carbon dioxide. Samples are taken and analyzed at minute intervals during the distraction process. The following process parameters are varied:
- initial pressure in the storage vessel - feed rate of the polymer solution - feed rate and quantity of the carbon dioxide - pressure of the carbon dioxide at the nozzle.
The back pressure at the nozzle, the residual methylene chloride content and the morphology and apparent density of the powder are analyzed.
Le A 28 369 - Foreign Countries 2~72~
~e~
The initial pressure9 i.e. the pressure in step (b), is 20 bar Feed rate 17.6 ml/min.
Quantity of C02 in nozzle, based on the total quantity of polymer solutian: 500%
Carbon dioxide introduced under a pressure of 130 bar at a temperature of 110C.
Result: nozzle back pressure 90 bar, residual methylene chloride content of all samples under 1%t completely amorphous powder in every case (characteri~ed by differential scanning colorimetry), apparent density 0.10 g/cm .
e 2 The initial pressure, i.e. the pressure in step (b), is 30 bar Feed rate of polymer solution: 31.4 ml/min.
Quantity of C02 in nozzle: 19.5 kg/hour Temperature of C02 before nozzle: 105C
Temperature of PC solution: 25C before the nozzle The expansion vessel was preheated to 70C and kept at that temperature. Pressure of the C02 before the noz~le: 90 bar.
Result: nozzle back pressure 85 bar, apparent density 0.07 g/cm , fine-particle amorphous powder, residual solvent content under- 1%. The powder was very free-flowing and did not agglomerate or cake.
Comparison Example No initial pressure, otherwise as in Example 1. The test had to be terminated after a few minutes because the no7zle was blocked. The powder nad an apparent density of 0.015 g/cc and had a low residual solvent content (~2%).
Le A 28 369 - Foreign Countries
Claims (3)
1. A continuous process for the isolation of polycarbonates from a solution of polycarbonate in methylene chloride at temperatures of 30 to 80°C said process yielding polycarbonate in powder form having residual solvent content of less than 5% by weight, comprising a) obtaining a solution of polycarbonate in methylene chloride containing 10 to 40 percent polycarbonate, said percent being relative to the total weight of the polycarbonate solution, b) mixing into said solution under pressures of 10 to 50 bar and at temperatures of 30 to 50°C a fluid containing carbon dioxide resulting in a non-gelling polycarbonate/methylene chloride/carbon dioxide pressurized system in which 10 to 12% CO2 are dissolved, c) mixing said pressurized system in a two-component nozzle with additional fluid containing carbon dioxide under a pressure of 50 to 300 bar and at temperatures of 40 to 150°C, to cause rapid precipitation of polycarbonate in the form of solid particles, the quantitative ratio of CO2 to solution being between 1.0 and 15.
f) separating methylene chloride and carbon dioxide gases in a compressor/condenser system said process being further characterized in that a time interval of at least 0.1 second separates step b) and step c), and in that the input of the fluid containing carbon dioxide is controlled to prevent gelation in step b) and in that the pressurized system is above the gelation range in step c).
f) separating methylene chloride and carbon dioxide gases in a compressor/condenser system said process being further characterized in that a time interval of at least 0.1 second separates step b) and step c), and in that the input of the fluid containing carbon dioxide is controlled to prevent gelation in step b) and in that the pressurized system is above the gelation range in step c).
2. The process of Claim 1 wherein said c) is carried out under a pressure of 70 to 200 bar.
3. The process of Claim 1 wherein said c) is carried out at temperatures of 80 to 120°C.
Le A 28 369-Foreign Countries
Le A 28 369-Foreign Countries
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4117751.7 | 1991-05-30 | ||
| DE4117751A DE4117751A1 (en) | 1991-05-30 | 1991-05-30 | METHOD FOR INSULATING POLYCARBONATES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2069721A1 true CA2069721A1 (en) | 1992-12-01 |
Family
ID=6432812
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002069721A Abandoned CA2069721A1 (en) | 1991-05-30 | 1992-05-27 | Process for isolating polycarbonates_with co2 under pressure |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US5221731A (en) |
| EP (1) | EP0515948A3 (en) |
| JP (1) | JPH05222184A (en) |
| CA (1) | CA2069721A1 (en) |
| DE (1) | DE4117751A1 (en) |
Families Citing this family (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4128683A1 (en) * | 1991-08-29 | 1993-03-04 | Bayer Ag | INSULATION OF POLY (ESTER) CARBONATES FROM METHYLENE CHLORIDE WITH THE HELP OF CARBON DIOXIDE FLUID |
| DE4130105A1 (en) * | 1991-09-11 | 1993-03-18 | Bayer Ag | CARBON DIOXIDE DESTRACTION OF POLYCARBONATE |
| US5306807A (en) * | 1993-07-30 | 1994-04-26 | General Electric Company | Process for isolating polymer resins from solutions |
| US6051256A (en) * | 1994-03-07 | 2000-04-18 | Inhale Therapeutic Systems | Dispersible macromolecule compositions and methods for their preparation and use |
| GB9413202D0 (en) * | 1994-06-30 | 1994-08-24 | Univ Bradford | Method and apparatus for the formation of particles |
| US5670614A (en) * | 1994-08-25 | 1997-09-23 | United States Surgical Corporation | Method of increasing the plasticity and/or elasticity of polymers via supercritical fluid extraction and medical devices fabricated therefrom |
| US5478921A (en) * | 1994-08-25 | 1995-12-26 | United States Surgical Corporation | Method of purifying bioabsorable polymer |
| US20030203036A1 (en) | 2000-03-17 | 2003-10-30 | Gordon Marc S. | Systems and processes for spray drying hydrophobic drugs with hydrophilic excipients |
| GB9703673D0 (en) * | 1997-02-21 | 1997-04-09 | Bradford Particle Design Ltd | Method and apparatus for the formation of particles |
| DE19806355C2 (en) | 1998-02-10 | 2003-04-03 | Der Gruene Punkt Duales Syst | Thermal separation process for blended polymers |
| GB9810559D0 (en) * | 1998-05-15 | 1998-07-15 | Bradford Particle Design Ltd | Method and apparatus for particle formation |
| GB9915975D0 (en) * | 1999-07-07 | 1999-09-08 | Bradford Particle Design Ltd | Method for the formation of particles |
| US7575761B2 (en) * | 2000-06-30 | 2009-08-18 | Novartis Pharma Ag | Spray drying process control of drying kinetics |
| AU2001277230A1 (en) * | 2000-08-01 | 2002-02-13 | Inhale Therapeutic Systems, Inc. | Apparatus and process to produce particles having a narrow size distribution andparticles made thereby |
| GB0027357D0 (en) | 2000-11-09 | 2000-12-27 | Bradford Particle Design Plc | Particle formation methods and their products |
| GB0208742D0 (en) | 2002-04-17 | 2002-05-29 | Bradford Particle Design Ltd | Particulate materials |
| GB0117696D0 (en) * | 2001-07-20 | 2001-09-12 | Bradford Particle Design Plc | Particle information |
| EP1446104B2 (en) | 2001-11-01 | 2011-08-03 | Novartis AG | Spray drying methods |
| US7582284B2 (en) * | 2002-04-17 | 2009-09-01 | Nektar Therapeutics | Particulate materials |
| GB0216562D0 (en) * | 2002-04-25 | 2002-08-28 | Bradford Particle Design Ltd | Particulate materials |
| US9339459B2 (en) | 2003-04-24 | 2016-05-17 | Nektar Therapeutics | Particulate materials |
| DE10234165B4 (en) * | 2002-07-26 | 2008-01-03 | Advanced Micro Devices, Inc., Sunnyvale | A method of filling a trench formed in a substrate with an insulating material |
| WO2004058218A2 (en) * | 2002-12-30 | 2004-07-15 | Nektar Therapeutics | Prefilming atomizer |
| EP1624862B1 (en) * | 2003-05-08 | 2014-12-31 | Nektar Therapeutics | Particulate materials |
| JP2007505136A (en) * | 2003-09-10 | 2007-03-08 | マツプ・フアーマシユーテイカルズ・インコーポレーテツド | Aerosol formulation for delivering dihydroergotamine to systemic circulation by pulmonary inhalation |
| EP2425819A1 (en) | 2007-02-11 | 2012-03-07 | MAP Pharmaceuticals Inc | Method of therapeutic administration of dhe to enable rapid relief of migraine while minimizing side effect profile |
| US9808030B2 (en) | 2011-02-11 | 2017-11-07 | Grain Processing Corporation | Salt composition |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA915005A (en) * | 1972-11-21 | The Government Of The United States Of America As Represented By The Sec Retary Of The Army | Flueric arming device | |
| NL7000597A (en) * | 1969-01-21 | 1970-07-23 | ||
| US4209912A (en) * | 1978-01-16 | 1980-07-01 | General Electric Company | Process and apparatus for the drying of resinous materials |
| DE3425125A1 (en) * | 1984-07-07 | 1986-01-16 | Bayer Ag, 5090 Leverkusen | METHOD FOR REMOVING UNWANTED REMAINING COMPONENTS, IN PARTICULAR LOW MOLECULAR COMPONENTS, FROM SOLID POLYMERS |
| US4634761A (en) * | 1984-12-14 | 1987-01-06 | General Electric Company | Continuous method for isolating polymer resin from solution wherein organic solvent resin solution is fed into aqueous feed |
| JPH0639524B2 (en) * | 1987-12-25 | 1994-05-25 | 出光石油化学株式会社 | Method for purifying polycarbonate |
| FI79033C (en) * | 1988-03-22 | 1989-11-10 | Ahlstroem Oy | FOERFARANDE OCH ANORDNING FOER EFFEKTIVERING AV FUNKTIONEN HOS SKIVFILTER. |
| JPH01242621A (en) * | 1988-03-23 | 1989-09-27 | Mitsubishi Gas Chem Co Inc | Preparation of purified polycarbonate resin |
| DE3840293A1 (en) * | 1988-11-30 | 1990-05-31 | Werner & Pfleiderer | METHOD FOR REMOVING IMPURITIES FROM POLYMERIC PLASTICS, AND DEVICE FOR CARRYING OUT THE METHOD |
| DE4118230A1 (en) * | 1990-12-20 | 1992-06-25 | Bayer Ag | METHOD OF ISOLATING POLYMERS FROM THEIR SOLVENTS WITH CARBON DIOXIDE-CONTAINING LIQUIDS |
-
1991
- 1991-05-30 DE DE4117751A patent/DE4117751A1/en not_active Withdrawn
-
1992
- 1992-05-19 EP EP19920108395 patent/EP0515948A3/en not_active Withdrawn
- 1992-05-26 JP JP4157286A patent/JPH05222184A/en active Pending
- 1992-05-26 US US07/888,942 patent/US5221731A/en not_active Expired - Fee Related
- 1992-05-27 CA CA002069721A patent/CA2069721A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| US5221731A (en) | 1993-06-22 |
| JPH05222184A (en) | 1993-08-31 |
| EP0515948A2 (en) | 1992-12-02 |
| EP0515948A3 (en) | 1993-03-31 |
| DE4117751A1 (en) | 1992-12-03 |
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