Patent US3621020A successfully refreshed from Google Patents.
US3621020A
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Process for trimerizing polyisocyanates
Assignee: EIDP Inc
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Filing: 1969-12-17
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Granted: 1971-11-16
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Expires: 1989-12-17
Abstract
Abstract A rapid and economical method for trimerizing organic polyisocyanates by mixing an organic polyisocyanate with substituted guanidine and/or isobiguanide catalysts. The catalysts exhibit high activity, usually requiring little or no heat to induce trimerization. The trimerized polyisocyanates are especially useful in the preparation of rigid polyurethane foams.
Inventors
- 👤 Leo Ojakaar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:31
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/77; C08G18/78; C08G18/79; C08G18/791; Y; Y10; Y10S; Y10S521/00; Y10S521/902
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
42 words
The process of claim 1 wherein the trimerization reaction is carried out at temperatures from about -10* to about 250* C. and the catalyst is present in the amount of abouT 0.001- 5.0 percent based on the weight of the organic polyisocyanate.
Claim 2
Dependent Claim
24 words
The process of claim 2 wherein each R group, R1 to R10, is independently C1-C4 alkyl, and each of X and X'' is hydrogen.
Claim 3
Dependent Claim
12 words
The process of claim 3 wherein the catalyst is 1,1,3,3-tetramethylguanidine or 1,1,4,4,5,5-hexamethylisobiguanide.
Claim 4
Dependent Claim
46 words
The process of claim 2 wherein the trimerization reaction is carried out at temperatures from about 20* to about 180* C. and the catalyst is used in the amount of about 0.05 to about 2.0 percent by weight based on the weight of the organic polyisocyanate.
Claim 5
Dependent Claim
24 words
The process of claim 5 wherein each R group, R1 to R10 is independently C1-C4 alkyl, and each of X and X'' is hydrogen.
Claim 6
Dependent Claim
10 words
The process of claim 6 wherein the catalyst is 1,1,3,3-tetramethylquanidine.
Claim 7
Dependent Claim
12 words
The process of claim 8 wherein the organic polyisocyanate is tolylene diisocyanate.
Claim 8
Dependent Claim
15 words
The process of claim 5, wherein each R group, R1to R10, is independently C1-C4 alkyl.
Claim 9
Dependent Claim
19 words
The process of claim 9, wherein each of the groups R1, R2, R3 and R4 is a methyl radical.
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) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |