Claims
- 1. A hollow fiber structure ultrafiltration membrane of substantially uniform cross section comprising a material of the polymethyl methacrylate series, said material being a mixture of a polymer rich in isotacticity and a polymer rich in sindiotacticity, said polymer having a molecular weight of 100,000 to 2,000,000 and containing substantially no ion pairs so that substantially no crosslinking is formed, and said membrane having a permeability of albumin of not less than 90% and a water UFBS of 2 to 30 l/hr.multidot.m.sup.2.mmHg.
- 2. A hollow fiber type ultrafiltration membrane claimed in claim 1, wherein the material is a copolymerized polymethyl methacrylate with a vinyl monomer other than methyl methacrylate.
- 3. A hollow fiber type ultrafiltration membrane claimed in claim 1, wherein the weight average molecular weight of the polymethyl methacrylate is not less than about 100,000.
- 4. A hollow fiber type ultrafiltration membrane claimed in claim 3, having a weight average molecular weight of 200,000 to 2,0000,000.
- 5. A hollow fiber type ultrafiltration membrane claimed in claim 4, having a weight average molecular weight of about 500,000 to 1,000,000.
- 6. The membrane defined in claim 1, wherein the material of the polymethyl methacrylate series is produced by common radical polymerization.
- 7. A process for preparation of a hollow fiber structure ultrafiltration membrane of substantially uniform cross section comprising discharging and coagulating a spinning solution through a hollow fiber spinneret wherein a material of the polymethyl methacrylate series is used, said material being a mixture of a polymer rich in isotacticity and a polymer rich in sindiotacticity, said polymer having a molecular weight of 100,000 to 2,000,000 and containing substantially no ion pair so that substantially no crosslinking is formed, and said membrane having a permeability of albumin of not less than 90% and a water UFRS of 2 to 30 liters/hr.m.sup.2.mmHg, an organic solvent containing a membrane pore size controlling agent is employed as the solvent, a solution having a polymer concentration of 5 to 30% by weight dissolved therein is spun, and the relation of T.sub.s (.degree.C.)-20<To<T.sub.s +40, where To (.degree.C.) is the spinneret temperature, T.sub.s (.degree.C.) is the phase separation temperature, is satisfied on the condition that the phase separation temperature T.sub.s is the temperature at which turbidity is observed when the temperature of the spinning solution is lowered at a rate of 1.degree.C./10 min.
- 8. A process for preparation of a hollow fiber type ultrafiltration membrane claimed in claim 7, wherein the organic solvent is selected from the group of dimethyl sulfoxide, dimethyl formamide, dimethyl acetamide, N-methyl pyrrolidone, acetonitril, acetone, methyl ethyl ketone, methyl cellosolve and methyl carbitol.
- 9. A process for preparation of a hollow fiber type ultrafiltration membrane claimed in claim 7, wherein the membrane pore size controlling agent is selectd from the group of water, formamide, alcohols, urea, calcium chloride, polyoxyethylene ester lauryl alcohol, and iso-octyl phenoxy polyethoxyethanol.
- 10. A process for preparation of a hollow fiber type ultrafiltration membrane claimed in claim 7, wherein the organic solvent is selected from dimethyl sulfoxide and dimethyl formamide, the membrane pore size controlling agent is selected from glycerin and formamide, and the solvent contains 5 to 40% of membrane pore size controlling agent.
- 11. A process for preparation of a hollow fiber type ultrafiltration membrane claimed in claim 7, wherein the hollow fiber spinneret is a spinneret composed of a ring-shaped orifice containing a hollow small size tube inside the spinneret hole, and the substance poured through the hollow tube into the inside of a hollow fiber is selected from among solvent, a mixture of solvent and water, a mixture of solvent and polyhydric alcohol, air and inert gas.
- 12. A process for preparation of a hollow fiber type ultrafiltration membrane claimed in claim 7, wherein the distance through which a spun substance passes in air or inert gas before being led from a spinneret to a coagulating bath is about from 0.5 to 100 cm.
- 13. A process for preparation of a hollow fiber type ultrafiltration membrane claimed in claim 7, wherein the distance through which a spun substance passes in air or inert gas before being led from a spinneret to a coagulating bath is about from 5 to 50 cm.
- 14. A process for preparation of a hollow fiber type ultrafiltration membrane claimed in claim 7, wherein the coagulating solution is water or a mixture of solvent and water, and the temperature of the coagulating bath is about from 0.degree. to 98.degree. C.
- 15. The process defined in claim 7 wherein the material of the polymethyl methacrylate series is produced by common radical polymerization.
Priority Claims (2)
Number |
Date |
Country |
Kind |
56-173099 |
Oct 1981 |
JPX |
|
57-80268 |
May 1982 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 517,517, filed 6/30/83, now abandoned.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/JP82/00422 |
10/28/1982 |
|
|
6/30/1983 |
6/30/1983 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO83/01632 |
5/11/1983 |
|
|
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
3615024 |
Michaels |
Oct 1971 |
|
3892665 |
Steigelmann |
Jul 1975 |
|
4439322 |
Sohoda et al. |
Mar 1984 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
517517 |
Jun 1983 |
|