Difficulty flammable extruded articles, especially extruded boards, and a process for making them
Abstract
Abstract The disclosure relates to difficultly flammable wooden articles, especially chip boards comprising solid and pipe boards, prepared by extrusion from wooden chips and/or woody fibrous materials. The articles contain as a flame-retarding addend a product of (a) 50 to 99.5 weight % of a flame-retarding agent physically and chemically stable under extrusion conditions, preferably 75 to 99.5 weight % of a pulverulent, free-flowing ammonium polyphosphate of the general formula H.sub.(n-m)+2 (NH.sub.4).sub.m P.sub.n O.sub.3n+1 in which n stands for a whole number with an average value of about 20 to 800 and the ratio of m/n is about 1, and (b) about 0.5 to 50 weight % of a cured water-insoluble artificial resin encapsulating the individual particles of the flame-retarding agent or ammonium polyphosphate. The disclosure also relates to difficultly flammable boards veneered with wood or a laminate.
Inventors
- 👤 Fritz-Reichard Fuchs
- 👤 Horst Staendeke
Bibliographic Details
Claims Analysis
Total Claims: 5References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |