Patent US3973074A successfully refreshed from Google Patents.
US3973074A
Expired / Lapsed
US
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Flame-proof cellulosic product
Assignee: MacMillan Bloedel Ltd
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Filing: 1975-03-19
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Granted: 1976-08-03
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Expires: 1995-03-19
Abstract
Abstract A flame-proof product comprising a cellulosic base, and particularly a wood based product having at least one surface treated with a composition which when the surface is subjected to fire or high temperatures combines with some of the material of the base to form a protective intumescent coating on the surface which insulates the remainder of the product from thermal destruction. The treating composition includes potassium hydroxide and/or potassium carbonate alone or mixed with a comparatively small amount of sodium hydroxide and/or sodium carbonate. The composition may in addition include potassium chloride, or potassium acetate, or potassium citrate, or potassium bicarbonate, or potassium bisulfite, or potassium metaphosphate, or potassium nitrite, or potassium sulfide, or potassium sulfite, or potassium thiosulfate, or potassium phosphate (tribasic).
Inventors
- 👤 Richard C. F. de Lissa
- 👤 Walter G. Schwarze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:19
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/18; C08K3/24; C08K3/26; C08K3/01; C08K3/016; C08K3/10; C08K3/20; Y; Y10; Y10S; Y10S260/00; Y10S260/24; Y10S428/00; Y10S428/92; Y10S428/921; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31971; Y10T428/31989
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
A flame-proof product comprising a cellulosic or wood base substrate having at its surface at least one fire retardant chemical compound selected from the group consisting of potassium hydroxide and potassium carbonate, said compound being provided at said surface in an amount of at least 75% by weight based on the total weight of fire retardant chemicals applied to said surface by drying a solution of said compound applied thereto, the amount of said compound at said surface being sufficient such that when said surface is subjected to high temperatures, said surface foams with decomposing cellulosic material to form a layer of relatively noncombustible intumescent carboniferous char.
Claim 2
Dependent Claim
107 words
A flame-proof product comprising a cellulosic or wood base substrate having at its surface at least one fire retardant chemical compound selected from the group consisting of potassium hydroxide and potassium carbonate, said compound being provided at said surface in an amount of at least 75% by weight based on the total weight of fire retardant chemicals applied to said surface by drying a solution of said compound applied thereto, the amount of said compound at said surface being sufficient such that when said surface is subjected to high temperatures, said surface foams with decomposing cellulosic material to form a layer of relatively noncombustible intumescent carboniferous char.
Claim 3
Dependent Claim
65 words
A flame-proof product as claimed in claim 1 in which said surface further includes up to 25% by weight of the total fire retardant chemicals applied to the surface of at least one fire retardant chemical selected from the group consisting of potassium acetate, potassium bicarbonate, potassium bisulfite, potassium chloride, potassium citrate, potassium metaphosphate, potassium nitrite, potassium sulfide, potassium sulfite, tripotassium phosphate, and potassium thiosulfate.
Claim 4
Dependent Claim
67 words
A flame-proof product as claimed in claim 1 in which said surface further includes up to 25% by weight of the total fire retardant chemicals applied to the surface of at least one chemical selected from the group consisting of sodium carbonate, sodium hydroxide, sodium acetate, sodium bicarbonate, sodium bisulfite, sodium chloride, sodium citrate, sodium metaphosphate, sodium nitrite, sodium sulfide, sodium sulfite, trisodium phosphate, and sodium thiosulfate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |