US4193814A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Binding lignocellulosic materials
Assignee: HER MAJESTY IN RIGHT OF CANADA FORESTRY, Minister of
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Filing: 1978-04-21
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Granted: 1980-03-18
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Expires: 1998-04-21
Abstract
Abstract A method of making a thermosetting binder for lignocellulosic materials, utilizing spent sulfite liquor, and a method of making a particleboard product. Spent sulfite liquor treated with sufficient sulfuric acid to provide a lignosulfonic acid content of not less than 0.8 milliequivalent weight of NaOH per gram of spent sulfite liquor solids, makes it possible to make particleboard with press time and physical properties comparable to phenol or urea formaldehyde bonded boards but at considerably reduced material cost.
Inventors
- 👤 Kuo-Cheng Shen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:43
CPC Classifications
C; C08; C08H; C08H6/00; B; B27; B27N; B27N1/00; B27N3/00; B27N3/002; C08L; C08L97/00; C08L97/02; C08L2201/00; C08L2201/02; C08L97/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
63 words
A method of making a thermosetting binder for lignocellulosic materials, comprising treating a concentrate of spent sulfite liquor with sufficient sulfuric acid to produce a lignosulfonic acid content of not less than 0.8 milliequivalent weight of NaOH per gram of spent sulfite liquor solids, the amount of sulfuric acid being not substantially greater than that required to release all the available lignosulfonic acid.
Claim 2
Independent Claim
63 words
A method of making a thermosetting binder for lignocellulosic materials, comprising treating a concentrate of spent sulfite liquor with sufficient sulfuric acid to produce a lignosulfonic acid content of not less than 0.8 milliequivalent weight of NaOH per gram of spent sulfite liquor solids, the amount of sulfuric acid being not substantially greater than that required to release all the available lignosulfonic acid.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the milliequivalent weight is not less than 1.2 per gram of spent sulfite liquor solids.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein the milliequivalent weight is not greater than 2 per gram of spent sulfite liquor solids.
Claim 5
Dependent Claim
9 words
The composition produced by the method of claim 3.
Claim 6
Dependent Claim
60 words
The method of claim 1 further comprising mixing the treated spent sulfite liquor with lignocellulosic particles in proportions of at least 3% treated spent sulfite liquor solids based on lignocellulosic particle weight, forming a mat with the mixture and hot pressing that mat at a temperature of not less than 177° C. for a time sufficient to cure the binder.
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) | 1983-03-18 | 1983-09-17 | 1984-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-18 | 1987-09-17 | 1988-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-18 | 1991-09-17 | 1992-03-18 | $7700.00 | Window Closed / Lapsed |