US4306943A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of polyether-polyol
Assignee: DKS Co Ltd
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Filing: 1981-03-12
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Granted: 1981-12-22
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Expires: 2001-03-12
Abstract
Abstract Crude liquid polyether-polyols containing an alkaline catalyst are purified by the steps of: neutralizing said crude liquid polyether-polyol with a mineral acid having a dissociation constant of greater than 10 -3 at 25° C. distilling off water from said liquid, and filtering the same. The improvement resides in the step of adding a hydrate of a metal salt of said mineral acid to the liquid polyether-polyol at a stage before the distillation step for promoting the crystal growth of a salt formed from said alkaline catalyst by the neutralization.
Inventors
- 👤 Shigeo Mori
- 👤 Takeshi Fujita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:19
CPC Classifications
C; C08; C08G; C08G65/00; C08G65/02; C08G65/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
88 words
In a method for purifying crude polyether-polyols containing an alkaline catalyst comprising the steps of: neutralizing said crude liquid polyether-polyol with a mineral acid having a dissociation constant of greater than 10 -3 at 25° C., distilling off water from said liquid, and filtering the same, the improvement which comprises adding a hydrate of a metal salt of said mineral acid to said liquid polyether-polyol at a stage before the distillation step for promoting the crystal growth of a salt formed from said alkaline catalyst by the neutralization.
Claim 2
Dependent Claim
88 words
In a method for purifying crude polyether-polyols containing an alkaline catalyst comprising the steps of: neutralizing said crude liquid polyether-polyol with a mineral acid having a dissociation constant of greater than 10 -3 at 25° C., distilling off water from said liquid, and filtering the same, the improvement which comprises adding a hydrate of a metal salt of said mineral acid to said liquid polyether-polyol at a stage before the distillation step for promoting the crystal growth of a salt formed from said alkaline catalyst by the neutralization.
Claim 3
Dependent Claim
22 words
The method according to claim 1, wherein an adsorbent is added to the neutralized liquid at a stage before the distillation step.
Claim 4
Dependent Claim
72 words
The method according to claim 1, wherein said mineral acid is selected from the group consisting of H 2 SO 4 , HCl, HNO 3 , HClO 2 , NHSO 3 H, H 2 S 2 O 3 , H 2 PO 2 , H 4 P 2 O 7 , HClO 3 , HIO 3 , H 3 PO 4 , H 3 PO 3 and H 2 SO 3 .
Claim 5
Dependent Claim
113 words
The method according to claim 1, wherein said hydrate is selected from the group consisting of Na 2 SO 3 .7H 2 O, Na 2 HPO 4 .12H 2 O, NaH 2 PO 4 .H 2 O, CaHPO 4 .2H 2 O, MgSO 4 .H 2 O, MgSO 4 .7H 2 O, K 2 Mg(SO 4 ) 2 .6H 2 O, Na 2 SO 4 .10H 2 O, CaSO 4 .2H 2 O, NaAl(SO 4 ) 2 .12H 2 O, KAl(SO 4 ) 2 .12H 2 O, ZnSO 4 .7H 2 O, Na 2 S 2 O 3 .5H 2 O, NaBr.2H 2 O, CaCl 2 .6H 2 O and NaBr.2H 2 O.
Claim 6
Dependent Claim
30 words
The method according to claim 2, wherein said adsorbent is selected from the group consisting of oxides, carbonates, hydroxides and silicates of Ca, Mg and Al, their complexes and bentonite.
Claim 7
Dependent Claim
35 words
The method according to claim 1, wherein said crude polyether-polyols are produced by reacting an organic compound having at least one active hydrogen atom with an alkylene oxide in the presence of an alkaline catalyst.
Claim 8
Dependent Claim
35 words
The method according to claim 6, wherein said organic compound having at least one hydrogen atom is selected from the group consisting of a monohydric alcohol, a dihydric alcohol, a polyhydric alcohol and an amine.
Claim 9
Dependent Claim
26 words
The method according to claim 6, wherein said alkylene oxide is selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and styrene oxide.
Claim 10
Dependent Claim
27 words
The method according to claim 6, wherein said alkaline catalyst is selected from the group consisting of metallic elements, alkoxides, hydroxides and carbonates of sodium and potassium.
Claim 11
Dependent Claim
17 words
The method according to claim 1, wherein said crude polyether-polyols are neutralized in the presence of water.
References Cited (Backward Citations)
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Cited
US3271462A
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US3326985A
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US3915674A
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US4137398A
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JPS55108823A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-21 | 1985-06-22 | 1985-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-21 | 1989-06-22 | 1989-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-21 | 1993-06-22 | 1993-12-22 | $7700.00 | Window Closed / Lapsed |