Claims
- 1. A process for removing alkali material from a polyether polyol produced by base-catalyzed polyaddition of an alkylene oxide, comprising:
- (a) adding from 1 to 20 percent by weight of water and from 0 to 30 percent by weight of an inert, organic solvent to the alkaline polyether polyol to form an emulsion;
- (b) maintaining the thus-formed emulsion at a temperature of at least 70.degree. C. for at least 30 minutes with little or no stirring to destabilize the emulsion and thereby promote separation of the emulsion into an organic and an aqueous phase;
- (c) separating the aqueous phase from the organic phase by passing the emulsion through a sheet-formed structure made of fine fibers, which sheet structure has a weight per unit area of from 100 to 10,000 g/m.sup.2 and a thickness of from 1 to 100 mm; and
- (d) removing residual alkaline material from the organic phase.
- 2. The process of claim 1 wherein from 2 to 10% by weight of water are added to the alkaline polyether polyol in step (a).
- 3. The process of claim 1 wherein the inert organic solvent is toluene.
- 4. The process of claim 1 wherein the emulsion is maintained at a temperature of from 85.degree. to 130.degree. C. in step (b).
- 5. The process of claim 1 wherein the fibers of the sheet-form structure have a thickness of less than 50 .mu.m.
- 6. The process of claim 7 wherein the fibers have a thickness of from 1 to 10 .mu.m.
- 7. The process of claim 1 wherein the rate of flow of the emulsion through the fibrous sheet-form structure is from 1 to 20 m/h.
- 8. The process of claim 1 wherein the sheet-form structure is made of metal or mineral fibers.
- 9. The process of claim 1 wherein step (d) comprises: adding an acid or an adsorbent material to the organic phase, filtering the resultant mixture, and distilling off any remaining water and organic solvent from the filtrate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
3016113 |
Apr 1980 |
DEX |
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Parent Case Info
This application is a continuation of application Ser. No. 251,432, filed Apr. 6, 1981, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
1082810 |
Sep 1967 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
251432 |
Apr 1981 |
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