US5140086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Isocyanate modified cellulose products and method for their manufacture
Assignee: Richwood Industries Inc
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Filing: 1990-11-27
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Granted: 1992-08-18
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Expires: 2010-11-27
Abstract
Abstract A method is disclosed for producing a polyureacellulose composite material from substantially delignified cellulosic material and an isocyanate resin. The isocyanate resin comprises a polyisocyanate, preferably PMDI, and a miscible organic solvent, preferably one such as propylene carbonate having a high boiling point and low flammability and toxicity. The composite surprisingly exhibits values of physical parameters that are at least as good as, and sometimes far superior to, corresponding parameters of similar composites made using neat (undiluted) polyisocyanate. Single- and multiple-ply composites can be made, employing only a single curing step.
Inventors
- 👤 Frank R. Hunter
- 👤 James F. L. Lincoln
- 👤 David W. Park
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:12
CPC Classifications
D; D21; D21H; D21H27/00; D21H27/30; B; B32; B32B; B32B23/00; B32B23/14; B32B23/16; C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/0838; C08G18/0842; C08G18/0847; C08G18/0852; C08G18/28; C08G18/30; C08G18/302; C08G18/40; C08G18/64; C08G18/6484; C08G18/70; C08G18/72; C08G18/74; C08G18/76; C08G18/7657; C08G18/7664; C08K; C08K5/00; C08K5/04; C08K5/15; C08K5/156; C08K5/1565; C08L; C08L1/00; C08L1/02; C08L97/00; C08L97/02; D21H17/00; D21H17/20; D21H17/33; D21H17/46; D21H17/54; D21H17/57; D21H25/00; D21H25/04; D21H25/06; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31971; Y10T428/31975; Y10T428/31978; Y10T428/31982; Y10T428/31986; Y10T428/31989
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
107 words
A method for making a polyurea-cellulose composite which comprises: impregnating a substantially delignified cellulosic material with an isocyanate resin comprising at least one polyisocyanate compound and a miscible organic solvent therefor, where the solvent comprises up to about 20% w/w of the polyisocyanate and the isocyanate resin constitutes about 8% to about 20% w/w of the cellulosic material so as to form a polyisocyanate-impregnated cellulosic material; and curing the polyisocyanate-impregnated cellulosic material at a temperature within a range of about 105° to about 245° C. for a time not exceeding about 5 minutes and at a pressure within a range of about 130 to about 1200 psig.
Claim 2
Independent Claim
107 words
A method for making a polyurea-cellulose composite which comprises: impregnating a substantially delignified cellulosic material with an isocyanate resin comprising at least one polyisocyanate compound and a miscible organic solvent therefor, where the solvent comprises up to about 20% w/w of the polyisocyanate and the isocyanate resin constitutes about 8% to about 20% w/w of the cellulosic material so as to form a polyisocyanate-impregnated cellulosic material; and curing the polyisocyanate-impregnated cellulosic material at a temperature within a range of about 105° to about 245° C. for a time not exceeding about 5 minutes and at a pressure within a range of about 130 to about 1200 psig.
Claim 3
Dependent Claim
77 words
The method of claim 1 in which the cellulosic material is in a sheet form having first and second sheet surfaces substantially parallel to each other and a Z or thickness dimension extending in a direction between the first and second sheet surfaces perpendicular to the first and second sheet surfaces, and wherein the isocyanate resin is substantially uniformly distributed throughout the Z or thickness dimension of the sheet after impregnating the sheet with the isocyanate resin.
Claim 4
Dependent Claim
25 words
The method of claim 1 in which the polyisocyanate is selected from the group consisting of lower aliphatic, alicyclic, and aromatic polyisocyanates, and mixtures thereof.
Claim 5
Dependent Claim
12 words
The method of claim 3 in which the polyisocyanate is poly(diphenylmethane diisocyanate).
Claim 6
Dependent Claim
29 words
The method of claim 1 in which the solvent is selected from the group consisting of alkylene carbonates, aromatics, halogenated aromatics, nitroaromatics, alkylated aromatics, ethers, ketones, and alkyl acetates.
Claim 7
Dependent Claim
27 words
The method of claim 1 in which the cellulosic material has a moisture content not exceeding about 10% w/w relative to the mass of the cellulosic material.
Claim 8
Dependent Claim
13 words
The method of claim 1 in which the isocyanate resin includes a catalyst.
Claim 9
Dependent Claim
33 words
The method of claim 7 in which the catalyst is present in the isocyanate resin in a concentration within a range of about 0.1 to about 0.5% w/w relative to the isocyanate resin.
Claim 10
Dependent Claim
24 words
The method of claim 7 in which the catalyst is selected from the group consisting of aliphatic tertiary amines, aliphatic metal complexes, and acetylacetonates.
Claim 11
Dependent Claim
22 words
The method of claim 9 in which the catalyst is selected from the group consisting of diazobicyclooctane, tin octoate, and dibutyltin dilaurate.
Claim 12
Dependent Claim
36 words
The method of claim 1 in which the cellulosic material is selected from the group consisting of pulped cellulose fibers; chemical pulps; thermomechanical pulps; bleached and unbleached paper and paper-like materials, non-woven mats, sheets, and felts.
Claim 13
Dependent Claim
22 words
The method of claim 1 in which the solvent comprises from about 5% w/w to about 20% w/w relative to the polyisocyanate.
Claim 14
Dependent Claim
31 words
The method of claim 12 in which the isocyanate resin includes a catalyst in a concentration within a range of about 0.1% to about 0.5% w/w relative to the isocyanate resin.
Claim 15
Dependent Claim
10 words
A polyurea-cellulose composite made by the method of claim 1.
Claim 16
Independent Claim
140 words
A method for making a laminated polyurea-cellulose composite material comprising the steps: individually impregnating each of plural sheets of substantially delignified cellulosic material with an isocyanate resin comprising at least one polyisocyanate compound, a miscible organic solvent therefor, and a catalyst, wherein the solvent comprises up to about 20% w/w of the polyisocyanate and the resin constitutes about 8 to about 20% w/w of the cellulosic material so as to form plural polyisocyanate-impregnated cellulosic lamina; plying at least two of the polyisocyanate-impregnated cellulosic lamina together so as to form a laminar stack of said polyisocyanate-impregnated cellulose lamina; and curing the stack of plied lamina at a temperature in a range of about 105° C. to about 245° C. for a time not exceeding about 5 minutes and at a pressure within a range of about 130 to about 1200 psig.
Claim 17
Independent Claim
140 words
A method for making a laminated polyurea-cellulose composite material comprising the steps: individually impregnating each of plural sheets of substantially delignified cellulosic material with an isocyanate resin comprising at least one polyisocyanate compound, a miscible organic solvent therefor, and a catalyst, wherein the solvent comprises up to about 20% w/w of the polyisocyanate and the resin constitutes about 8 to about 20% w/w of the cellulosic material so as to form plural polyisocyanate-impregnated cellulosic lamina; plying at least two of the polyisocyanate-impregnated cellulosic lamina together so as to form a laminar stack of said polyisocyanate-impregnated cellulose lamina; and curing the stack of plied lamina at a temperature in a range of about 105° C. to about 245° C. for a time not exceeding about 5 minutes and at a pressure within a range of about 130 to about 1200 psig.
Claim 18
Dependent Claim
22 words
The method of claim 15 in which the polyisocyanate-impregnated cellulosic material is plied on at least one face of a rigid substrate.
Claim 19
Dependent Claim
25 words
The method of claim 16 in which the substrate is selected from the group consisting of wood, wood veneer, reconstituted wood products, and wood-containing composites.
Claim 20
Dependent Claim
39 words
The method of claim 15 in which the cellulosic material is selected from the group consisting of pulped cellulose fibers; chemical pulps; thermomechanical pulps; recycled pulp fiber; bleached and unbleached paper and paper-like materials, non-woven mats, sheets, and felts.
Claim 21
Dependent Claim
25 words
The method of claim 15 in which the polyisocyanate is selected from the group consisting of lower aliphatic, alicyclic, and aromatic polyisocyanates, and mixtures thereof.
Claim 22
Dependent Claim
12 words
The method of claim 19 in which the polyisocyanate is poly(diphenylmethane diisocyanate).
Claim 23
Dependent Claim
29 words
The method of claim 15 in which the solvent is selected from the group consisting of alkylene carbonates, aromatics, halogenated aromatics, nitroaromatics, alkylated aromatics, ethers, ketones, and alkyl acetates.
Claim 24
Dependent Claim
12 words
The method of claim 21 in which the solvent is propylene carbonate.
Claim 25
Dependent Claim
30 words
The method of claim 15 in which the catalyst is present in the isocyanate resin at a concentration of about 0.1 to about 0.5% w/w relative to the isocyanate resin.
Claim 26
Dependent Claim
25 words
The method of claim 23 in which the catalyst is selected from the group consisting of aliphatic tertiary amines, aliphatic metal complexes, and acetyl acetonates.
Claim 27
Dependent Claim
22 words
The method of claim 24 in which the catalyst is selected from the group consisting of diazobicyclooctane, tin octoate, and dibutyltin dilaurate.
Claim 28
Dependent Claim
28 words
The method of claim 15 in which the cellulosic material has a moisture content not exceeding about 7 percent w/w relative to the mass of the cellulosic material.
Claim 29
Dependent Claim
11 words
A laminated polyurea-cellulose composite made by the method of claim 15.
Claim 30
Independent Claim
112 words
A method for making a polyurea-cellulose composite, comprising the steps: impregnating a substantially delignified cellulosic material with a resin comprising an isocyanate compound and propylene carbonate, wherein the propylene carbonate is present in the resin at a concentration of up to about 20% w/w relative to the polyisocyanate and the resin constitutes about 8% to about 20% w/w of the cellulosic material, so as to form a polyisocyanate-impregnated cellulosic material; and curing the polyisocyanate-impregnated cellulosic material at a temperature within a range of about 105° C. to about 245° C. for a time not exceeding about 5 minutes and at a pressure within a range of about 130 to about 1200 psig.
Claim 31
Independent Claim
112 words
A method for making a polyurea-cellulose composite, comprising the steps: impregnating a substantially delignified cellulosic material with a resin comprising an isocyanate compound and propylene carbonate, wherein the propylene carbonate is present in the resin at a concentration of up to about 20% w/w relative to the polyisocyanate and the resin constitutes about 8% to about 20% w/w of the cellulosic material, so as to form a polyisocyanate-impregnated cellulosic material; and curing the polyisocyanate-impregnated cellulosic material at a temperature within a range of about 105° C. to about 245° C. for a time not exceeding about 5 minutes and at a pressure within a range of about 130 to about 1200 psig.
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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) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |