US3644232A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame-resistant, nonbursting polyisocyanurate foams
Assignee: Bayer Corp
•
Filing: 1968-05-24
•
Granted: 1972-02-22
•
Expires: 1988-05-24
Abstract
Abstract Polyisocyanurate foams are prepared by reacting an organic polyisocyanurate mixture of polyphenyl polymethylene polyisocyanates wherein from about 10 to about 70 percent of the total methylene groups are ortho to at least one NCO group and from about 2 percent to about 20 percent of the total methylene groups are ortho to two NCO groups on adjacent aromatic rings. The polyisocyanurate foam is prepared from this mixture of isocyanates in the presence of a trimerization catalyst and an inert blowing agent and preferably a foam stabilizer. These foams when subjected to a flame do not pop and burst into fragments.
Inventors
- 👤 David L Bernard
- 👤 John K Backus
- 👤 William C Darr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:06
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/02; C08G18/06; C08G18/08; C08G18/09; C08G18/70; C08G18/72; C08G18/74; C08G18/76; C08G18/7657; C08G18/7664; Y; Y10; Y10S; Y10S260/00; Y10S260/24; Y10S521/00; Y10S521/902
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
28 words
The polyisocyanurate foam of claim 1 wherein said mixture of isocyanates contains about 30 percent 4,4''-diphenylmethane diisocyanate, 20 percent 2,4''-diphenylmethane diisocyanate, 3 percent 2,2''-diphenylmethane diisocyanate, 10 percent of
Claim 2
Dependent Claim
14 words
The polyisocyanurate foam of claim 1 wherein said inert blowing agent is a halohydrocarbon.
Claim 3
Dependent Claim
12 words
The polyisocyanurate foam of claim 1 wherein said catalyst is 2,4,6-tris-(dimethylaminomethyl) phenol.
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) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |