US4026875A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for deactivating the catalyst in a polyurethane prepolymer
Assignee: Sika Schweiz AG
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Filing: 1976-04-07
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Granted: 1977-05-31
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Expires: 1996-04-07
Abstract
Abstract A method of manufacturing polyurethane prepolymers containing free, reactive end groups of polyisocyanate and compounds with active H-atoms, while using a tertiary amine as the catalyst, and thereafter deactivating the catalyst by reacting with an alkyl halide.
Inventors
- 👤 Gerhard Leu
- 👤 Ueli Sulser
- 👤 Jurg Widmer
- 👤 Heinz Goeth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:48
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/16; C08G18/089; C08G18/18; C08G18/20; C08G18/2045; C08G18/2063
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
74 words
In a method for manufacturing polyurethane prepolymers with free, reactive end groups prepared from polyisocyanates and compounds with active H-atoms in the presence of a tertiary amine as the catalyst, which prepolymers without further treatment tend to increase in viscosity on aging, the improvement comprising deactivating the catalyst by mixing an effective amount of tetrabromo ethane with the prepolymer, whereby the tendency of the prepolymer to increase in viscosity on aging is substantially reduced.
Claim 2
Dependent Claim
74 words
In a method for manufacturing polyurethane prepolymers with free, reactive end groups prepared from polyisocyanates and compounds with active H-atoms in the presence of a tertiary amine as the catalyst, which prepolymers without further treatment tend to increase in viscosity on aging, the improvement comprising deactivating the catalyst by mixing an effective amount of tetrabromo ethane with the prepolymer, whereby the tendency of the prepolymer to increase in viscosity on aging is substantially reduced.
Claim 3
Dependent Claim
15 words
The method as defined in claim 1, wherein the catalyst is an aliphatic tertiary amine.
Claim 4
Dependent Claim
15 words
The method as defined in claim 1, wherein the catalyst is a cycloaliphatic tertiary amine.
Claim 5
Dependent Claim
14 words
The method as defined in claim 1, wherein the catalyst is 1,4-diazobicyclo [2.2.2] octane.
Claim 6
Dependent Claim
19 words
The method as defined in claim 1, wherein the prepolymer is prepared in the presence of a dehydrating agent.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |