US5151238A
Expired / Lapsed
US
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Process for producing composite materials
Assignee: BTG International Ltd
•
Filing: 1989-06-05
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Granted: 1992-09-29
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Expires: 2009-06-05
Abstract
Abstract Process for producing a composite material in which a cellulosic substrate is treated with a solution of a polyfunctional isocyanate in an aprotic swelling solvent and the substrate is then compressed to form the composite material. The substrate may take the form of wood chips, wood particles, wood flakes, wood fibers, wood flour, ground wood, wood veneers and wood laminates, paper, card, straw, refined cellulose such as cotton or viscose and plant fibers such as bamboo or palm fiber.
Inventors
- 👤 Harold A. Earl
- 👤 William B. Banks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:02
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/28; C08G18/40; C08G18/64; C08G18/6484; C08L; C08L97/00; C08L97/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
55 words
A process for the production of a composite material, which process comprises the steps of: immersing a cellulosic substrate in a solution of a di-functional isocyanate in an aprotic swelling solvent to cause said cellulosic substrate to swell, said cellulosic substrate reacting with said isocyanate; and then compressing the substrate to form a composite material.
Claim 2
Dependent Claim
55 words
A process for the production of a composite material, which process comprises the steps of: immersing a cellulosic substrate in a solution of a di-functional isocyanate in an aprotic swelling solvent to cause said cellulosic substrate to swell, said cellulosic substrate reacting with said isocyanate; and then compressing the substrate to form a composite material.
Claim 3
Dependent Claim
18 words
A process according to claim 1 wherein the solution comprises from 0.1 to 5.0 moles/liter of di-functional isocyanate.
Claim 4
Dependent Claim
13 words
A process according to claim 1 wherein the di-functional isocyanate is a polyisocyanate.
Claim 5
Dependent Claim
13 words
A process according to claim 3 wherein the di-functional isocyanate is a di-isocyanate.
Claim 6
Dependent Claim
28 words
A process according to claim 4 wherein the di-isocyanate is selected from the group, consisting of hexamethylene diisocyanate, 2,4 toluene diisocyanate, 2,6 toluene diisocyanate and diphenyl methane diisocyanate.
Claim 7
Dependent Claim
21 words
A process according to claim 1 wherein the immersing is carried out for a period of from 0.02 to 200 hours.
Claim 8
Dependent Claim
20 words
A process according to claim 1 wherein the solvent is selected from the group consisting of pyridine, acetone and 2-methyl-2-pyrrolidinones.
Claim 9
Dependent Claim
23 words
A process according to claim 1 characterised in that the immersing is carried out at a temperature of from 25° to 150° C.
Claim 10
Dependent Claim
21 words
A process according to claim 1 characterised in that the compressing carried out at a temperature of less than 200° C.
Claim 11
Dependent Claim
23 words
A process according to claim 9 characterised in that the compressing is carried out at a temperature of from 125° to 175° C.
Claim 12
Dependent Claim
22 words
A process according to claim 1 characterised in that the compressing is applied for a period of from 2 to 30 minutes.
References Cited (Backward Citations)
GB1148016A
Cited
FR2127925A5
Cited
US3930097A
Cited
US3870665A
Cited
US4029846A
Cited
GB2076414A
Cited
JPS58189278A
Cited
US4623499A
Cited
US4752637A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-29 | 1996-03-30 | 1996-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-29 | 2000-03-30 | 2000-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-29 | 2004-03-30 | 2004-09-29 | $7700.00 | Window Closed / Lapsed |