Method of preparing a urea-formaldehyde combination foam that is low in formaldehyde
Abstract
Abstract A U.F. foam that is diamensionally stable, but low in formaldehyde, was made by adding to a conventional solution of a urea formaldehyde resin precondensate, before foaming, up to 50% urea, relative to the solid resin substance, and one or several connecting agents from the group of sulfurous alkyl compounds, saturated monobasic carbonic acids, saturated and unsaturated dicarbonic acids, purine compounds, inorganic acids of the group of halogens and chalcogens, and their salts, phosphoric acids and their salts, alkali metal salts and alkaline earth metal salts, in such quantity and in such a way that the pH of the resulting solution remains above 7; and subsequently foaming the solution with a hardener/foaming-agent solution in the conventional manner.
Inventors
- 👤 Heinz Baumann
Bibliographic Details
Claims Analysis
Total Claims: 3References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-26 | 1989-02-25 | 1989-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-26 | 1993-02-25 | 1993-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-26 | 1997-02-25 | 1997-08-27 | $7700.00 | Window Closed / Lapsed |