US4772392A — Process for preparing POWADIR membranes from tetr…

Claim 1

Independent Claim 458 words

A process for preparing a POWADIR hollow fiber membrane comprising a tetrahalogenated bisphenol polycarbonate which comprises: (A) forming a mixture comprising (i) a bisphenol polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is chlorine or bromine; (ii) a solvent for the polycarbonate which comprises a glycol ether which corresponds to the formula R 3 O--(CH 2 CH 2 O) r --R 3 wherein R 3 is methyl or ethyl, and r is an integer of between about 1 and 20: a dialkyl ketone wherein the alkyl groups independently are methyl or ethyl; morpholine substituted on the nitrogen atom with an alkyl, formyl or alkanoyl moiety; an unsubstituted or N--C 1-4 alkyl, N--C 5-6 cycloalkyl, or N--C 6-10 aryl or alkaryl substituted pyrrolidinone; C 1-4 alkoxycarbonyl, formyl, nitro, or halo substituted benzene; tetrahydrofuran; dimethylformamide, cyclohexanone; N,N-dimethyl acetamide; acetophenone; methylene chloride; or sulfolane; cyclohexyl acetate; 1,1,3,3-tetramethylurea; isophorone; caprolactone; 1-formylpiperidine; methyl salicylate; hexamethylphosphoramide; phenyl ether; or bromonaphthalene; and, (iii) a non-solvent for the polycarbonate which comprises a glycol or glycol ether which corresponds to the formula R 4 O--(CH 2 CH 2 O) q --R 4 wherein R 4 is independently in each occurrence hydrogen or C 1-4 alkyl, and q is an integer of about 1 to about 50; an ester corresponding to the formula R 5 COOR 6 wherein R 5 is hydrogen or C 1-19 alkyl, and R 6 is C 1-10 alkyl; a C 1-10 alkanol; cyclohexane, unsubstituted or substituted with an alkyl, cycloalkyl, or perfluoroalkyl moiety; a C 5-20 alkane; a dialkyl ketone wherein at least one of the alkyl moieties is C 3 or greater; an amide corresponding to the formula R 7 CONHR 8 wherein R 7 is hydrogen or C 1-10 alkyl and R 8 is C 1-10 alkyl; an acetyl or C 1-10 alkyl nitrile; acetone; a C 1-10 alkyl aldehyde; a trialkyl amine; nitromethane; trialkyl orthoformate; diacetone alcohol; dimethyl malonate; decahydronaphthalene; tetra-hydronaphthalene; malononitrile; dicyclohexyl; ethylene carbonate; sulfolane; alkyl or cycloalkyl substituted benzene; or water; wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; (B) heating the mixture to a temperature at which the mixture forms a homogeneous fluid and is extrudable; (C) extruding the heated mixture into a hollow fiber form; and (D) passing the formed fiber through one or more quench zones wherein the mixture phase separates, and the major portion of the solvent and non-solvent are removed from the formed membrane while a core fluid is passed down the hollow core of the fiber under conditions sufficient to prevent the fiber from collapsing; wherein the fiber formed is a POWADIR fiber with a discriminating region capable of separating oxygen from nitrogen.

Claim 2

Dependent Claim 458 words

A process for preparing a POWADIR hollow fiber membrane comprising a tetrahalogenated bisphenol polycarbonate which comprises: (A) forming a mixture comprising (i) a bisphenol polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is chlorine or bromine; (ii) a solvent for the polycarbonate which comprises a glycol ether which corresponds to the formula R 3 O--(CH 2 CH 2 O) r --R 3 wherein R 3 is methyl or ethyl, and r is an integer of between about 1 and 20: a dialkyl ketone wherein the alkyl groups independently are methyl or ethyl; morpholine substituted on the nitrogen atom with an alkyl, formyl or alkanoyl moiety; an unsubstituted or N--C 1-4 alkyl, N--C 5-6 cycloalkyl, or N--C 6-10 aryl or alkaryl substituted pyrrolidinone; C 1-4 alkoxycarbonyl, formyl, nitro, or halo substituted benzene; tetrahydrofuran; dimethylformamide, cyclohexanone; N,N-dimethyl acetamide; acetophenone; methylene chloride; or sulfolane; cyclohexyl acetate; 1,1,3,3-tetramethylurea; isophorone; caprolactone; 1-formylpiperidine; methyl salicylate; hexamethylphosphoramide; phenyl ether; or bromonaphthalene; and, (iii) a non-solvent for the polycarbonate which comprises a glycol or glycol ether which corresponds to the formula R 4 O--(CH 2 CH 2 O) q --R 4 wherein R 4 is independently in each occurrence hydrogen or C 1-4 alkyl, and q is an integer of about 1 to about 50; an ester corresponding to the formula R 5 COOR 6 wherein R 5 is hydrogen or C 1-19 alkyl, and R 6 is C 1-10 alkyl; a C 1-10 alkanol; cyclohexane, unsubstituted or substituted with an alkyl, cycloalkyl, or perfluoroalkyl moiety; a C 5-20 alkane; a dialkyl ketone wherein at least one of the alkyl moieties is C 3 or greater; an amide corresponding to the formula R 7 CONHR 8 wherein R 7 is hydrogen or C 1-10 alkyl and R 8 is C 1-10 alkyl; an acetyl or C 1-10 alkyl nitrile; acetone; a C 1-10 alkyl aldehyde; a trialkyl amine; nitromethane; trialkyl orthoformate; diacetone alcohol; dimethyl malonate; decahydronaphthalene; tetra-hydronaphthalene; malononitrile; dicyclohexyl; ethylene carbonate; sulfolane; alkyl or cycloalkyl substituted benzene; or water; wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; (B) heating the mixture to a temperature at which the mixture forms a homogeneous fluid and is extrudable; (C) extruding the heated mixture into a hollow fiber form; and (D) passing the formed fiber through one or more quench zones wherein the mixture phase separates, and the major portion of the solvent and non-solvent are removed from the formed membrane while a core fluid is passed down the hollow core of the fiber under conditions sufficient to prevent the fiber from collapsing; wherein the fiber formed is a POWADIR fiber with a discriminating region capable of separating oxygen from nitrogen.

Claim 3

Dependent Claim 97 words

The process of claim 1 wherein the polycarbonate corresponds to the formula ##STR4## wherein R at each occurrence is independently H, Cl, Br, or C 1 -C 4 alkyl; and, R 1 is carbonyl, --S--, --SO 2 --, --O--, or a C 1 -C 6 divalent hydrocarbon, a C 1 -C 6 divalent halocarbon radical, or an inertly substituted C 1 -C6 hydrocarbon radical, with the proviso that at least 25 weight percent of the moieties derived from the bisphenol of Formula I present in the discriminating layer bear R groups which are exclusively Br or Cl.

Claim 4

Dependent Claim 86 words

The process of claim 2 wherein the fiber is passed from the extruder into an air quench zone, under conditions such that a portion of the solvent is removed from the fibers and the fiber undergoes draw down in said air quench zone, and from the air quench zone the fiber is passed into one or more liquid quench zones under conditions such that the fiber substantially completes phase separation and the solvent and non-solvent are substantially removed from the fiber in said liquid quench zones.

Claim 5

Dependent Claim 69 words

The process of claim 3 wherein the fiber is passed through two liquid quench zones wherein the fiber is passed through the first liquid zone under conditions such that the fiber undergoes significant phase separation in said bath, and the fiber is passed through the second liquid bath under conditions such that the solvent and non-solvent are substantially removed from the fiber and the fiber substantially completes phase separation.

Claim 6

Dependent Claim 27 words

The process of claim 4 wherein the remainder of the R groups are hydrogen or C 1-4 alkyl, and R 1 is a C 1-6 divalent hydrocarbon.

Claim 7

Dependent Claim 25 words

The process of claim 5 wherein the remainder of the R groups are hydrogen or methyl and R 1 is a C 1-6 alkylidine moiety.

Claim 8

Dependent Claim 29 words

The process of claim 6 wherein at least 50 weight percent of the bisphenol moieties present in the discriminating layer bear R groups which are exclusively Br or Cl.

Claim 9

Dependent Claim 27 words

The process of claim 7 wherein 100 weight percent of the bisphenol moieties present in the discriminating layer bear R groups which are exclusively Br or Cl.

Claim 10

Dependent Claim 27 words

The process of claim 8 wherein at least 50 weight percent of the bisphenol moieties present in the discriminating layer bear R groups which are exclusively Br.

Claim 11

Dependent Claim 20 words

The process of claim 9 wherein 100 weight percent of the bisphenol moieties bear R groups which are exclusively bromine.

Claim 12

Dependent Claim 11 words

The process of claim 10 wherein the bisphenol is tetrabromobisphenol A.

Claim 13

Dependent Claim 48 words

The process of claim 7 wherein the mixture comprises between about 40 and about 60 percent by weight of polycarbonate and between about 40 and about 60 percent by weight of solvent and non-solvent wherein the ratio of solvent to non-solvent is between about 1.7 and about 5.1.

Claim 14

Dependent Claim 99 words

The process of claim 12 wherein the solvent for the polycarbonate comprises N-methyl pyrrolidinone, tetrahydrofuran, ethylene glycol dimethyl ether, diethyl ketone, N-ethyl morpholine, dimethyl formamide, cyclohexanone, bis(2-methoxyethyl ether), N,N-dimethyl acetamide, acetophenone, methylene chloride, sulfolane, or mixtures thereof; and the non-solvent for the polycarbonate comprises triethylene glycol, 2-ethoxyethanol, diethylene glycol dibutyl ether, polyethylene glycols with a molecular weight of between about 400 and about 1450, triethylene glycol, diethylene glycol, dodecane, hexadecane, cyclohexane, methylcyclohexane, perchloroethylene, diisopropyl ketone, isopropyl ketone, isopropyl cyclohexane, t-butyl cyclohexane, N-methyl formamide, decaline, N-methyl acetamide, tetralin, dicyclohexyl, cyclohexyl benzene, diethylene glycol dibutylether, carbon tetrachloride, water, or mixtures thereof.

Claim 15

Dependent Claim 57 words

The process of claim 13 wherein the solvent non-solvent pair is N-methyl pyrrolidone and triethylene glycol, ethylene glycol dimethyl ether and water, tetrahydrofuran and water, ethylene glycol dimethyl ether and diisopropyl ketone, tetrahydrofuran and diisopropyl ketone, diethylene glycol dimethyl ether and water, acetophenone and diethylene glycol dibutyl ether, methylene chloride and carbon tetrachloride, or acetophenone and hexadecane.

Claim 16

Dependent Claim 16 words

The process of claim 14 wherein the solvent non-solvent pair is N-methyl pyrrolidone and triethylene glycol.

Claim 17

Dependent Claim 38 words

The process of claim 13 wherein the mixture is heated prior to extrusion to a temperature of between about 50° and 200° C. and the mixture is extruded at a temperature of between about 50° and 200° C.

Claim 18

Dependent Claim 50 words

The process of claim 16 wherein the fiber is contacted with the first liquid quench zone which comprises water at a temperature of between about ° and about 30° C. and the second liquid quench zone which comprises water at a temperature of between about 70° and about 100° C.

Claim 19

Dependent Claim 54 words

The process of claim 17 wherein the residence time of the fiber in the air quench zone is between about 0.25 and about 1 second, in the first liquid quench zone is between about 0.1 and about 600 seconds, and in the second liquid quench zone is between about 1 and about 30 minutes.

Claim 20

Dependent Claim 28 words

The process of claim 18 wherein the fiber after removal from the second liquid quench zone contains less than about 1.5 percent by weight of solvent and non-solvent.

Claim 21

Dependent Claim 23 words

The process of claim 19 wherein the fiber has a separation factor of 6.0 or greater for oxygen and nitrogen at 24° C.

Claim 22

Dependent Claim 22 words

The process of claim 20 wherein the fiber has a flux of 3.0 (1×10 -6 ) scc/cm 2 cmHg sec or greater.

Claim 23

Dependent Claim 459 words

A POWADIR hollow fiber membrane comprising a tetrahalogenated bisphenol polycarbonate prepared by the process which comprises: (A) forming a mixture comprising (i) a bisphenol polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is chlorine or bromine; (ii) a solvent for the polycarbonate which comprises a glycol ethery which corresponds to the formula R 3 O--(CH 2 CH 2 O ) r --R 3 wherein R 3 is methyl or ethyl, and r is an integer of between about 1 and 20; a dialkyl ketone wherein the alkyl groups independently are methyl or ethyl; morpholine substituted on the nitrogen atom with an alkyl, formyl or alkanoyl moiety; an unsubstituted or N--C 1-4 alkyl, N--C 5-6 cycloalkyl, or N--C 6-10 aryl or alkaryl substituted pyrrolidinone; C 1-4 alkoxycarbonyl, formyl, nitro, or halo substituted benzene; tetrahydrofuran; dimethylformamide, cyclohexanone; N,N-dimethyl acetamide; acetophenone; methylene chloride; or sulfolane; cyclohexyl acetate; 1,1,3,3-tetramethylurea; isophorone; caprolactone; 1-formylpiperidine; methyl salicylate; hexamethylphosphoramide; phenyl ether; or bromonaphthalene; and, (iii) a non-solvent for the polycarbonate which comprises a glycol or glycol ether which corresponds to the formula R 4 O--(CH 2 CH 2 O) q -R 4 wherein R 4 is independently in each occurrence hydrogen or C 1-4 alkyl, and q is an integer of about 1 to about 50; an ester corresponding to the formula R 5 COOR 6 wherein R 5 is hydrogen or C 1-19 alkyl, and R 6 is C 1-10 alkyl; a C 1-10 alkanol; cyclohexane, unsubstituted or substituted with an alkyl, cycloalkyl, or perfluoroalkyl moiety; a C 5-20 alkane; a dialkyl ketone wherein at least one of the alkyl moieties is C 3 or greater; an amide corresponding to the formula R 7 CONHR 8 wherein R 7 is hydrogen or C 1-10 alkyl and R 8 is C 1-10 alkyl; an acetyl or C 1-10 alkyl nitrile; acetone a C 1-10 alkyl aldehyde; a trialkyl amine; nitromethane; trialkyl orthoformate; diacetone alcohol; dimethyl malonate; decahydronaphthalene; tetrahydronaphthalene; malononitrile; dicyclohexyl; ethylene carbonate; sulfolane; alkyl or cycloalkyl substituted benzene; or water; wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; (B) heating the mixture to a temperature at which the mixture forms a homogeneous fluid and is extrudable; (C) extruding the heated mixture into a hollow fiber form; and (D) passing the formed fiber through one or more quench zones wherein the mixture phase separates, and the major portion of the solvent and non-solvent are removed from the formed membrane while a core fluid is passed down the hollow core of the fiber under conditions sufficient to prevent the fiber from collapsing; wherein the fiber formed is a POWADIR fiber with a discriminating region capable of separating oxygen from nitrogen.

Claim 24

Dependent Claim 459 words

A POWADIR hollow fiber membrane comprising a tetrahalogenated bisphenol polycarbonate prepared by the process which comprises: (A) forming a mixture comprising (i) a bisphenol polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is chlorine or bromine; (ii) a solvent for the polycarbonate which comprises a glycol ethery which corresponds to the formula R 3 O--(CH 2 CH 2 O ) r --R 3 wherein R 3 is methyl or ethyl, and r is an integer of between about 1 and 20; a dialkyl ketone wherein the alkyl groups independently are methyl or ethyl; morpholine substituted on the nitrogen atom with an alkyl, formyl or alkanoyl moiety; an unsubstituted or N--C 1-4 alkyl, N--C 5-6 cycloalkyl, or N--C 6-10 aryl or alkaryl substituted pyrrolidinone; C 1-4 alkoxycarbonyl, formyl, nitro, or halo substituted benzene; tetrahydrofuran; dimethylformamide, cyclohexanone; N,N-dimethyl acetamide; acetophenone; methylene chloride; or sulfolane; cyclohexyl acetate; 1,1,3,3-tetramethylurea; isophorone; caprolactone; 1-formylpiperidine; methyl salicylate; hexamethylphosphoramide; phenyl ether; or bromonaphthalene; and, (iii) a non-solvent for the polycarbonate which comprises a glycol or glycol ether which corresponds to the formula R 4 O--(CH 2 CH 2 O) q -R 4 wherein R 4 is independently in each occurrence hydrogen or C 1-4 alkyl, and q is an integer of about 1 to about 50; an ester corresponding to the formula R 5 COOR 6 wherein R 5 is hydrogen or C 1-19 alkyl, and R 6 is C 1-10 alkyl; a C 1-10 alkanol; cyclohexane, unsubstituted or substituted with an alkyl, cycloalkyl, or perfluoroalkyl moiety; a C 5-20 alkane; a dialkyl ketone wherein at least one of the alkyl moieties is C 3 or greater; an amide corresponding to the formula R 7 CONHR 8 wherein R 7 is hydrogen or C 1-10 alkyl and R 8 is C 1-10 alkyl; an acetyl or C 1-10 alkyl nitrile; acetone a C 1-10 alkyl aldehyde; a trialkyl amine; nitromethane; trialkyl orthoformate; diacetone alcohol; dimethyl malonate; decahydronaphthalene; tetrahydronaphthalene; malononitrile; dicyclohexyl; ethylene carbonate; sulfolane; alkyl or cycloalkyl substituted benzene; or water; wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; (B) heating the mixture to a temperature at which the mixture forms a homogeneous fluid and is extrudable; (C) extruding the heated mixture into a hollow fiber form; and (D) passing the formed fiber through one or more quench zones wherein the mixture phase separates, and the major portion of the solvent and non-solvent are removed from the formed membrane while a core fluid is passed down the hollow core of the fiber under conditions sufficient to prevent the fiber from collapsing; wherein the fiber formed is a POWADIR fiber with a discriminating region capable of separating oxygen from nitrogen.

Claim 25

Dependent Claim 100 words

The product by process of claim 22 wherein the polycarbonate corresponds to the formula ##STR5## wherein R at each occurrence is independently H, Cl, Br, or C 1 -C 4 alkyl; and, R 1 is carbonyl, --S--, --SO 2 --, --O--, or a C 1 -C 6 divalent hydrocarbon, a C 1 -C 6 divalent halocarbon radical, or an inertIy substituted C 1 -C 6 hydrocarbon radical, with the proviso that at least 25 weight percent of the moieties derived from the bisphenol of formula I present in the discriminating layer bear R groups which are exclusively Br or Cl.

Claim 26

Dependent Claim 88 words

The product by process of claim 23 wherein the fiber is passed from the extruder into an air quench zone, under conditions such that a portion of the solvent is removed from the fibers and the fiber undergoes draw down in said air quench zone, and from the air quench zone the fiber is passed into one or more liquid quench zones under conditions such that the fiber substantially completes phase separation and the solvent and non-solvent are substantially removed from the fiber in said liquid quench zones.

Claim 27

Dependent Claim 70 words

The product by process of claim 24 wherein the fiber is passed through two liquid quench zones wherein the fiber is passed through the first liquid zone under conditions such that the fiber undergoes significant phase separation in said bath, and the fiber is passed through the second liquid bath under conditions such that the solvent and non-solvent are substantially removed from the fiber and phase separation is substantially completed.

Claim 28

Dependent Claim 29 words

The product by process of claim 25 wherein the remainder of the R groups are hydrogen or C 1-4 alkyl, and R 1 is a C 1-6 divalent hydrocarbon.

Claim 29

Dependent Claim 27 words

The product by process of claim 26 wherein the remainder of the R groups are hydrogen or methyl and R 1 is a C 1-6 alkylidine moiety.

Claim 30

Dependent Claim 29 words

The product by process of claim 27 wherein 100 weight percent of the bisphenol moieties present in the discriminating layer bear R groups which are exclusively Br or Cl.

Claim 31

Dependent Claim 50 words

The product by process of claim 28 wherein the mixture comprises between about 40 and about 60 percent by weight of polycarbonate and between about 40 and about 60 percent by weight of solvent and non-solvent wherein the ratio of solvent to non-solvent is between about 1.7 and about 5.1.

Claim 32

Dependent Claim 34 words

The product by process of claim 29 wherein the fiber has a porous outer surface, a porous inner surface, and functions as if it has a discriminating layer capable of separating oxygen and nitrogen.

Claim 33

Dependent Claim 30 words

The product by process of claim 30 wherein the fiber has a porous outer surface, a porous inner surface, and an internal discriminating region capable of separating oxyge and nitrogen.

Claim 34

Dependent Claim 240 words

A POWADIR hollow fiber comprising tetrabromobisphenol A polycarbonate prepared by the process which comprises: (A) forming a mixture comprising tetrabromo-bisphenol A polycarbonate, N-methyl pyrrolidone, and triethylene glycol, wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; (B) heating the mixture to a temperature at which the mixture forms a homogeneous fluid and is extrudable; (C) extruding the heated mixture into a hollow fiber form; (D) passing the formed fiber through an air quench zone wherein the fiber undergoes partial removal of the solvent and the fiber is drawn down, while a core fluid is passed down the hollow core of the fiber under conditions sufficient to prevent the fiber from collapsing; (E) passing the fiber into a first water quench zone at a temperature at which the polycarbonate undergoes substantial phase separation and the major portion of the N-methyl pyrrolidone and triethylene glycol are removed from the formed fiber; and (F) passing the fiber into a second water quench zone wherein the second water zone is at a temperature at which a majority of the remaining N-methyl pyrrolidone and triethylene glycol is removed and phase separation is substantially completed; wherein the fiber formed is a POWADIR fiber with a discriminating region capable of separating oxygen from nitrogen and has a separation factor of about 6.0 or greater, and a flux of 3.0 (1×10 -6 ) scc/cm 2 cmHg sec or greater.

Claim 35

Dependent Claim 240 words

A POWADIR hollow fiber comprising tetrabromobisphenol A polycarbonate prepared by the process which comprises: (A) forming a mixture comprising tetrabromo-bisphenol A polycarbonate, N-methyl pyrrolidone, and triethylene glycol, wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; (B) heating the mixture to a temperature at which the mixture forms a homogeneous fluid and is extrudable; (C) extruding the heated mixture into a hollow fiber form; (D) passing the formed fiber through an air quench zone wherein the fiber undergoes partial removal of the solvent and the fiber is drawn down, while a core fluid is passed down the hollow core of the fiber under conditions sufficient to prevent the fiber from collapsing; (E) passing the fiber into a first water quench zone at a temperature at which the polycarbonate undergoes substantial phase separation and the major portion of the N-methyl pyrrolidone and triethylene glycol are removed from the formed fiber; and (F) passing the fiber into a second water quench zone wherein the second water zone is at a temperature at which a majority of the remaining N-methyl pyrrolidone and triethylene glycol is removed and phase separation is substantially completed; wherein the fiber formed is a POWADIR fiber with a discriminating region capable of separating oxygen from nitrogen and has a separation factor of about 6.0 or greater, and a flux of 3.0 (1×10 -6 ) scc/cm 2 cmHg sec or greater.

Claim 36

Dependent Claim 41 words

The product by process of claim 32 wherein the mixture comprises: (A) between about 40 and about 60 percent by weight of tetrabromobisphenol A polycarbonate; and (B) between about 40 and about 60 percent by weight of N-methylpyrrolidone and triethylene glycol.

Claim 37

Dependent Claim 81 words

The product by process of claim 33 wherein the mixture is heated prior to extrusion to a temperature of between about 90° and 130° C., and is extruded at a temperature of between about 70° and about 130° C., the fiber is contacted with the first water quench zone at a temperature of between about 0° and about 30° C., and the fiber is contacted with the second water quench zone at a temperature of between about 80° and 90° C.

Claim 38

Dependent Claim 68 words

The product by process of claim 34 wherein the residence time of the fiber in the air quench zone is between about 0.25 and about 1.0 second, the residence time of the fiber in the first water quench zone is between about 0.1 and about 300 seconds, and the residence time of the fiber in the second water quench zone is between about 5 and about 10 minutes.

Claim 39

Dependent Claim 413 words

A process for preparing a POWADIR membrane comprising tetrahalogenated bisphenol polycarbonate which comprises: (A) forming a mixture comprising (i) a bisphenol polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is chlorine or bromine; (ii) a solvent for the polycarbonate which comprises a glycol ether which corresponds to the formula R 3 O--(CH 2 CH 2 O) r -R 3 wherein R 3 is methyl or ethyl, and r is an integer of between about 1 and 20; a dialkyl ketone wherein the alkyl groups independently are methyl or ethyl; morpholine substituted on the nitrogen atom with an alkyl, formyl or alkanoyl moiety; unsubstituted or N--C 1-4 alkyl, N--C 5-6 cycloalkyl, or N--C 6-10 aryl or alkaryl substituted pyrrolidinone; C 1-4 alkoxycarbonyl, formyl, nitro, or halo substituted benzene; tetrahydrofuran; dimethyl formamide; cyclohexanone; N,N-dimethyl acetamide; acetophenone; methylene chloride; sulfolane; cyclohexyl acetate; 1,1,3,3-tetramethylurea; isophorone; caprolactone; 1-formylpiperidine; methyl salicylate; hexamethylphosphoramide; phenyl ether; or bromonaphthalene; and, (iii) a non-solvent for the polycarbonate which comprises a glycol or glycol ether which corresponds to the formula R 4 O--(CH 2 CH 2 O) q -R 4 wherein R 4 is independently in each occurrence hydrogen or C 1-4 alkyl, and q is an integer of about 1 to about 50; an ester corresponding to the formula R 5 COOR 6 wherein R 5 is hydrogen or C 1-19 alkyl, and R 6 is C 1-10 alkyl; a C 1-10 alkanol; cyclohexane, unsubstituted or substituted with an alkyl, cycloalkyl, or perfluoroalkyl moiety; a C 5-20 alkane; a dialkyl ketone wherein at least one of the alkyl moieties is C 3 or greater; an amide corresponding to the formula R 7 CONHR 8 wherein R 7 is hydrogen or C 1-10 alkyl and R 8 is C 1-10 alkyl; an acetyl or C 1-10 alkyl nitrile; acetone; a C 1-10 alkyl aldehyde; a trialkyl amine; nitromethane; trialkyl orthoformate; diacetone alcohol; dimethyl malonate decahydronaphthalene; tetrahydronaphthalene; malononitrile; dicyclohexyl; ethylene carbonate; sulfolane; alkyl or cycloalkyl substituted benzene; or water; (B) heating the mixture to a temperature at which the mixture is a homogeneous fluid and extrudable; (C) extruding the heated mixture into a shape suitable for membrane use; (D) passing the formed membrane through one or more quench zones wherein the mixture phase separates, and the major portion of the solvent and non-solvent are removed from the formed membrane; and wherein the membrane formed is POWADIR with a discriminating region capable of separating oxygen from nitrogen.

Claim 40

Dependent Claim 413 words

A process for preparing a POWADIR membrane comprising tetrahalogenated bisphenol polycarbonate which comprises: (A) forming a mixture comprising (i) a bisphenol polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated wherein the halogen is chlorine or bromine; (ii) a solvent for the polycarbonate which comprises a glycol ether which corresponds to the formula R 3 O--(CH 2 CH 2 O) r -R 3 wherein R 3 is methyl or ethyl, and r is an integer of between about 1 and 20; a dialkyl ketone wherein the alkyl groups independently are methyl or ethyl; morpholine substituted on the nitrogen atom with an alkyl, formyl or alkanoyl moiety; unsubstituted or N--C 1-4 alkyl, N--C 5-6 cycloalkyl, or N--C 6-10 aryl or alkaryl substituted pyrrolidinone; C 1-4 alkoxycarbonyl, formyl, nitro, or halo substituted benzene; tetrahydrofuran; dimethyl formamide; cyclohexanone; N,N-dimethyl acetamide; acetophenone; methylene chloride; sulfolane; cyclohexyl acetate; 1,1,3,3-tetramethylurea; isophorone; caprolactone; 1-formylpiperidine; methyl salicylate; hexamethylphosphoramide; phenyl ether; or bromonaphthalene; and, (iii) a non-solvent for the polycarbonate which comprises a glycol or glycol ether which corresponds to the formula R 4 O--(CH 2 CH 2 O) q -R 4 wherein R 4 is independently in each occurrence hydrogen or C 1-4 alkyl, and q is an integer of about 1 to about 50; an ester corresponding to the formula R 5 COOR 6 wherein R 5 is hydrogen or C 1-19 alkyl, and R 6 is C 1-10 alkyl; a C 1-10 alkanol; cyclohexane, unsubstituted or substituted with an alkyl, cycloalkyl, or perfluoroalkyl moiety; a C 5-20 alkane; a dialkyl ketone wherein at least one of the alkyl moieties is C 3 or greater; an amide corresponding to the formula R 7 CONHR 8 wherein R 7 is hydrogen or C 1-10 alkyl and R 8 is C 1-10 alkyl; an acetyl or C 1-10 alkyl nitrile; acetone; a C 1-10 alkyl aldehyde; a trialkyl amine; nitromethane; trialkyl orthoformate; diacetone alcohol; dimethyl malonate decahydronaphthalene; tetrahydronaphthalene; malononitrile; dicyclohexyl; ethylene carbonate; sulfolane; alkyl or cycloalkyl substituted benzene; or water; (B) heating the mixture to a temperature at which the mixture is a homogeneous fluid and extrudable; (C) extruding the heated mixture into a shape suitable for membrane use; (D) passing the formed membrane through one or more quench zones wherein the mixture phase separates, and the major portion of the solvent and non-solvent are removed from the formed membrane; and wherein the membrane formed is POWADIR with a discriminating region capable of separating oxygen from nitrogen.

Claim 41

Dependent Claim 75 words

The process of claim 36 wherein the mixture is passed from the extruder into an air quench zone, under conditions such that a portion of the solvent is removed from the mixture, and from the air quench zone the mixture is passed into one or more liquid quench zones under conditions such that the fiber substantially completes phase separation and the solvent and non-solvent are substantially removed from the mixture in said liquid quench zones.

Claim 42

Dependent Claim 68 words

The process of claim 37 wherein the mixture is passed through two liquid quench zones wherein the mixture is passed through the first liquid zone under conditions such that the mixture undergoes significant phase separation in said bath, and the fiber is passed through the second liquid bath under conditions such that the solvent and non-solvent are substantially removed from the mixture and phase separation is substantially completed.

Claim 43

Dependent Claim 19 words

The process of claim 38 wherein the membrane shape is a hollow tube, a sheet, or a hollow fiber.

Claim 44

Dependent Claim 98 words

The process of claim 39 wherein the polycarbonate corresponds to the formula ##STR6## wherein R at each occurrence is independently H, Cl, Br, or C 1 -C 4 alkyl; and R 1 is carbonyl, --S--, --SO 2 --, --O--, or a C 1 -C 6 divalent hydrocarbon, a C 1 -C 6 divalent halocarbon radical, or an inertly substituted C 1 -C 6 hydrocarbon radical, with the proviso that at least 25 weight percent of the moieties derived from the bisphenol of Formula I present in the discriminating layer bear R groups which are exclusively Br or Cl.

Claim 45

Dependent Claim 27 words

The product of claim 40 wherein 100 weight percent of the bisphenol moieties present in the discriminating layer bear R groups which are exclusively Br or Cl.

Claim 46

Dependent Claim 27 words

The product of claim 41 wherein at least 50 weight percent of the bisphenol moieties present in the discriminating layer bear R groups which are exclusively Br.

Claim 47

Dependent Claim 13 words

The product by process of claim 42 wherein the bisphenol is tetrabromobisphenol A.

Claim 48

Dependent Claim 63 words

The product of claim 43 wherein the solvent is N-methyl pyrrolidone, ethylene glycol dimethyl ether, tetrahydrofuran, diethylene glycol dimethyl ether, acetophenone, methylene chloride, or cyclohexanone; and the non-solvent is water, diisopropyl ketone, tetraethylene glycol dimethyl ether, diethylene glycol dibutyl ether, hexadecane, diethylene glycol, triethylene glycol, polyethylene glycol with a molecular weight of between about 400 and about 1450, 2-ethoxyethanol, carbon tetrachloride, or dodecane.

Claim 49

Dependent Claim 66 words

The product of claim 44 wherein the solvent non-solvent pair is N-methyl pyrrolidone and triethylene glycol, ethylene glycol dimethyl ether and water, tetrahydrofuran and water, ethylene glycol dimethyl ether and diisopropyl ketone, tetrahydrofuran and diisopropyl ketone, diethylene glycol dimethyl ether and water, diethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether, acetophenone and diethylene glycol dibutyl ether, methylene chloride and carbon tetrachloride, or acetophenone and hexadecane.

Claim 50

Dependent Claim 16 words

The product of claim 45 wherein the solvent non-solvent pair is N-methyl pyrrolidone and triethylene glycol.

Claim 51

Dependent Claim 322 words

A process for preparing POWADIR hollow fiber comprising tetrabromobisphenol A polycarbonate which comprises: (A) forming a mixture which comprises between about 40 and 60 percent by weight of (i) tetrabromobisphenol A polycarbonate; and (ii) between about 40 and 60 percent by weight of N-methyl pyrrolidone; and triethylene glycol wherein the ratio of N-methyl pyrrolidone to triethylene glycol is between about 1.8:1.0 and about 2.7:1.0 wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; (B) heating the mixture to a temperature of between about 50° and about 200° C. at which temperature the mixture is a homogeneous fluid and extrudable; (C) extruding the heated mixture into a hollow fiber form at a temperature of between about 50° and about 200° C.; (D) passing the formed fiber through an air quench zone wherein the fiber loses a portion of the solvent, while a core fluid is passed down the hollow core of the fiber under conditions sufficient to prevent the fiber from collapsing, wherein the residence time of the fiber in the air quench zone is between about 0.25 and about 1.0 seconds; (E) passing the fiber into a first water quench zone at a temperature of between about 0° and 30° C. for a period of between about 0.1 and about 600 seconds wherein the mixture undergoes significant phase separation, and the major portion of the N-methyl pyrrolidone and triethylene glycol are removed from the formed fiber; and (F) passing the fiber into a second water quench zone at a temperature of between about 70° and 100° C. for a period of between about 2 and about 30 minutes, wherein a majority of the remaining N-methylpyrrolidone and triethylene glycol is removed and the phase separation is substantially completed; wherein the fiber formed is a POWADIR fiber with a discriminating region capable of separating oxygen from nitrogen with a separation factor of 6.0 or greater.

Claim 52

Dependent Claim 322 words

A process for preparing POWADIR hollow fiber comprising tetrabromobisphenol A polycarbonate which comprises: (A) forming a mixture which comprises between about 40 and 60 percent by weight of (i) tetrabromobisphenol A polycarbonate; and (ii) between about 40 and 60 percent by weight of N-methyl pyrrolidone; and triethylene glycol wherein the ratio of N-methyl pyrrolidone to triethylene glycol is between about 1.8:1.0 and about 2.7:1.0 wherein the mixture has a sufficient viscosity to allow extrusion at temperatures at which the mixture is homogeneous; (B) heating the mixture to a temperature of between about 50° and about 200° C. at which temperature the mixture is a homogeneous fluid and extrudable; (C) extruding the heated mixture into a hollow fiber form at a temperature of between about 50° and about 200° C.; (D) passing the formed fiber through an air quench zone wherein the fiber loses a portion of the solvent, while a core fluid is passed down the hollow core of the fiber under conditions sufficient to prevent the fiber from collapsing, wherein the residence time of the fiber in the air quench zone is between about 0.25 and about 1.0 seconds; (E) passing the fiber into a first water quench zone at a temperature of between about 0° and 30° C. for a period of between about 0.1 and about 600 seconds wherein the mixture undergoes significant phase separation, and the major portion of the N-methyl pyrrolidone and triethylene glycol are removed from the formed fiber; and (F) passing the fiber into a second water quench zone at a temperature of between about 70° and 100° C. for a period of between about 2 and about 30 minutes, wherein a majority of the remaining N-methylpyrrolidone and triethylene glycol is removed and the phase separation is substantially completed; wherein the fiber formed is a POWADIR fiber with a discriminating region capable of separating oxygen from nitrogen with a separation factor of 6.0 or greater.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1991-09-20	1992-03-21	1992-09-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1995-09-20	1996-03-21	1996-09-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1999-09-20	2000-03-21	2000-09-20	$7700.00	Window Closed / Lapsed

Process for preparing POWADIR membranes from tetrahalobisphenol A polycarbonates

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag