US4134837A — Ethylene-vinyl alcohol copolymer membranes having…

Claim 1

Independent Claim 75 words

A separation membrane formed from an ethylene-vinyl alcohol copolymer wherein said membrane has a micropore structure which is substantially uniform throughout its longitudinal and transerse sectional areas and wherein its constituent particles have an average diameter in the range of 100 to 10000 Angstrom units as electron-microscopically determined for a dry membrane and are bonded to each other to form a membrane that is substantially free from pores in excess of 2 microns in diameter.

Claim 2

Dependent Claim 75 words

A separation membrane formed from an ethylene-vinyl alcohol copolymer wherein said membrane has a micropore structure which is substantially uniform throughout its longitudinal and transerse sectional areas and wherein its constituent particles have an average diameter in the range of 100 to 10000 Angstrom units as electron-microscopically determined for a dry membrane and are bonded to each other to form a membrane that is substantially free from pores in excess of 2 microns in diameter.

Claim 3

Dependent Claim 38 words

The separation membrane of claim 1 wherein said membrane is made of an ethylene-vinyl alcohol copolymer with an ethylene content of 10 to 90 mole percent and a degree of saponification of not less than 80 mole percent.

Claim 4

Dependent Claim 38 words

The separation membrane of claim 1 wherein said membrane is made of an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent.

Claim 5

Dependent Claim 17 words

The separation membrane of claim 1, which is produced by wet coagulation of an ethylene-vinyl alcohol copolymer.

Claim 6

Dependent Claim 119 words

A separation membrane with excellent blood dialyzing characteristics as formed from an ethylene-vinyl alcohol copolymer, wherein said membrane has a micropore structure which is substantially uniform throughout its longitudinal and transverse sectional areas and wherein its constituent particles have an average diameter in the range of 100 to 10000 Angstrom units as electron-microscopically determined for a dry membrane and are bonded to each other to form a membrane, that it is substantially free from pores in excess of 2 microns in diameter and that said membrane has a permeability to water of 10 to 200 × 10 -16 cm 2 and a permeability to vitamin B 12 of not less than 0.8 × 10 -7 cm 2 per second.

Claim 7

Dependent Claim 119 words

A separation membrane with excellent blood dialyzing characteristics as formed from an ethylene-vinyl alcohol copolymer, wherein said membrane has a micropore structure which is substantially uniform throughout its longitudinal and transverse sectional areas and wherein its constituent particles have an average diameter in the range of 100 to 10000 Angstrom units as electron-microscopically determined for a dry membrane and are bonded to each other to form a membrane, that it is substantially free from pores in excess of 2 microns in diameter and that said membrane has a permeability to water of 10 to 200 × 10 -16 cm 2 and a permeability to vitamin B 12 of not less than 0.8 × 10 -7 cm 2 per second.

Claim 8

Independent Claim 150 words

A method for producing a separation membrane characterized in that said method comprises dissolving an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent in a solvent selected from the group consisting of dimethylacetamide, methylpyrrolidone and dimethylsulfoxide to a polymer concentration (C) in the range of 10 to 35 percent by weight and introducing the resulting solution into a coagulation bath to coagulate said solution into a shaped article wherein said coagulation bath consists essentially of water and from 0 to 50% of a solvent selected from the group consisting of dimethylacetamide, methylpyrrolidone and dimethylsulfoxide at a coagualtion bath temperature (T° C) within the range defined by the following relation: When 10 ≦ C ≦ 25, 0 ≦ T ≦ C-10 (1) When 35 ≧ C ≧ 25, C-25 ≦ T ≦ C-8 (2)

Claim 9

Independent Claim 150 words

A method for producing a separation membrane characterized in that said method comprises dissolving an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent in a solvent selected from the group consisting of dimethylacetamide, methylpyrrolidone and dimethylsulfoxide to a polymer concentration (C) in the range of 10 to 35 percent by weight and introducing the resulting solution into a coagulation bath to coagulate said solution into a shaped article wherein said coagulation bath consists essentially of water and from 0 to 50% of a solvent selected from the group consisting of dimethylacetamide, methylpyrrolidone and dimethylsulfoxide at a coagualtion bath temperature (T° C) within the range defined by the following relation: When 10 ≦ C ≦ 25, 0 ≦ T ≦ C-10 (1) When 35 ≧ C ≧ 25, C-25 ≦ T ≦ C-8 (2)

Claim 10

Dependent Claim 10 words

the separation membrane prepared by the process of claim 6.

Claim 11

Independent Claim 138 words

A method for producing a separation membrane characterized in that said method comprises dissolving an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent in a solvent consisting essentially of dimethylsulfoxide to a polymer concentration (C) in the range of 10 to 35 weight percent, introducing the resulting solution into a coagulation bath to coagulate into said solution and form a shaped article wherein said coagulation bath consists essentially of water at a coagulation bath temperature (T° C) in the range defined by the following relation: When 10 ≦ C < 25, 0 ≦ T ≦ C-10 (1) When 35 ≧ C ≧ 25, C-25 ≦ T ≦ C-8 (2) and holding the resultant membrane in substantially wet condition without drying it.

Claim 12

Independent Claim 138 words

A method for producing a separation membrane characterized in that said method comprises dissolving an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent in a solvent consisting essentially of dimethylsulfoxide to a polymer concentration (C) in the range of 10 to 35 weight percent, introducing the resulting solution into a coagulation bath to coagulate into said solution and form a shaped article wherein said coagulation bath consists essentially of water at a coagulation bath temperature (T° C) in the range defined by the following relation: When 10 ≦ C < 25, 0 ≦ T ≦ C-10 (1) When 35 ≧ C ≧ 25, C-25 ≦ T ≦ C-8 (2) and holding the resultant membrane in substantially wet condition without drying it.

Claim 13

Independent Claim 168 words

A method for producing a separation membrane characterized in that said method comprises dissolving an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent in a solvent consisting essentially of dimethylsulfoxide to a polymer concentration (C) in the range of 10 to 35 weight percent, introducing the resulting solution into a coagulation bath to coagulate into said solution and form a shaped article wherein said coagulation bath consists essentially of water at a coagulation bath temperature (T° C) in the range defined by the following relation: When 10 ≦ C < 25, 0 ≦ T ≦ C-10 (1) When 35 ≧ C ≧ 25, C-25 ≦ T ≦ C-8 (2) and replacing the water inside and on the membrane so formed with an organic solvent which is miscible with water and in which said copolymer is not soluble, followed by drying at a temperature below the glass transition point of said copolymer.

Claim 14

Independent Claim 168 words

A method for producing a separation membrane characterized in that said method comprises dissolving an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent in a solvent consisting essentially of dimethylsulfoxide to a polymer concentration (C) in the range of 10 to 35 weight percent, introducing the resulting solution into a coagulation bath to coagulate into said solution and form a shaped article wherein said coagulation bath consists essentially of water at a coagulation bath temperature (T° C) in the range defined by the following relation: When 10 ≦ C < 25, 0 ≦ T ≦ C-10 (1) When 35 ≧ C ≧ 25, C-25 ≦ T ≦ C-8 (2) and replacing the water inside and on the membrane so formed with an organic solvent which is miscible with water and in which said copolymer is not soluble, followed by drying at a temperature below the glass transition point of said copolymer.

Claim 15

Dependent Claim 28 words

The method of claim 9 wherein said organic solvent is selected from the group consisting of lower aliphatic alcohols and ketones having 1 to 5 carbon atoms each.

Claim 16

Dependent Claim 44 words

The method of claim 10 wherein said polyhydric aliphatic alcohol is selected from the group consisting of polyhydric aliphatic alcohols of 2 to 4 carbon atoms and products of reacting 1 to 20 moles of ethylene oxide with any of said polyhydric aliphatic alcohols.

Claim 17

Dependent Claim 11 words

The method of claim 10 wherein said organic solvent is acetone.

Claim 18

Dependent Claim 12 words

The method of claim 10 wherein said polyhydric aliphatic alcohol is glycerin.

Claim 19

Independent Claim 146 words

A method for producing a separation membrane characterized in that said method comprises dissolving an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent in a solvent consisting essentially of dimethylsulfoxide to a polymer concentration (C) in the range of 10 to 35 weight percent, introducing the resulting solution into a coagulation bath to coagulate into said solution and form a shaped article wherein said coagulation bath consists essentially of water at a coagulation bath temperature (T° C) in the range defined by the following relation: When 10 ≦ C < 25, 0 ≦ T ≦ C-10 (1) When 35 ≧ C ≧ 25, C-25 ≦ T ≦ C-8 (2) and treating the membrane after forming with a polyhydric alcohol, followed by drying at a temperature not exceeding 50° C.

Claim 20

Independent Claim 146 words

A method for producing a separation membrane characterized in that said method comprises dissolving an ethylene-vinyl alcohol copolymer with an ethylene content of 15 to 60 mole percent and a degree of saponification of not less than 95 mole percent in a solvent consisting essentially of dimethylsulfoxide to a polymer concentration (C) in the range of 10 to 35 weight percent, introducing the resulting solution into a coagulation bath to coagulate into said solution and form a shaped article wherein said coagulation bath consists essentially of water at a coagulation bath temperature (T° C) in the range defined by the following relation: When 10 ≦ C < 25, 0 ≦ T ≦ C-10 (1) When 35 ≧ C ≧ 25, C-25 ≦ T ≦ C-8 (2) and treating the membrane after forming with a polyhydric alcohol, followed by drying at a temperature not exceeding 50° C.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1982-01-15	1982-07-17	1983-01-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1986-01-15	1986-07-17	1987-01-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1990-01-15	1990-07-17	1991-01-16	$7700.00	Window Closed / Lapsed

Ethylene-vinyl alcohol copolymer membranes having improved permeability characteristics and a method for producing the same

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag