US4244846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sulfite waste liquor-urea formaldehyde resin plywood glue
Assignee: Individual
•
Filing: 1979-10-22
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Granted: 1981-01-13
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Expires: 1999-10-22
Abstract
Abstract A plywood glue comprises an aqueous mixture of from 30-90 parts by weight urea formaldehyde resin, from 10-70 parts waste liquor from the acid sulfite pulping of lignocellulose, an amylaceous filler and from 0-2 to 4.0% ammonium ion (expressed as NH 3 ), based on the waste liquor solids. Prior to mixing, the sulfite waste liquor component of the mixture has a pH of from 3-9; the urea formaldehyde resin, a pH of from 6-9. The urea formaldehyde resin is further characterized by a molar ratio of formaldehyde to urea of from 1.2 to 2.5 and a methylol content corresponding to a Witte number of from 1.0 to 2.2. Plywood is made using the herein described glue by applying to the surfaces of wood veneers a bonding quantity of the glue, assembling the adhesive-coated veneers, and pressing the resulting assembly to cure the glue and bond the veneers together.
Inventors
- 👤 Folke J. Edler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:22
CPC Classifications
C; C08; C08L; C08L97/00; C08L97/02; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31942; Y10T428/31949; Y10T428/31957
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
148 words
A plywood glue comprising in aqueous admixture with each other and in parts by weight, dry solids basis: Urea-Formaldehyde Resin--30-90 Spent Liquor from the Acid Sulfite Pulping of Lignocellulose--10-70 the glue including also a filler comprising an amylaceous plywood glue filler used in the amount of from 30 to 300 parts for each 100 parts of the mixture of resin and spent liquor, the glue containing from 0.2 to 4.0% by weight ammonium ion (expressed as NH 3 ) on a spent liquor solids basis, the spent liquor component of the mixture prior to mixing having a pH of from 3-9, the urea formaldehyde resin component of the mixture prior to mixing being characterized by a mol ratio of formaldehyde to urea of from 1.2 to 2.5; a pH of from 6 to 9; and a methylol content corresponding to a Witte number of from 1.0 to 2.2.
Claim 2
Dependent Claim
148 words
A plywood glue comprising in aqueous admixture with each other and in parts by weight, dry solids basis: Urea-Formaldehyde Resin--30-90 Spent Liquor from the Acid Sulfite Pulping of Lignocellulose--10-70 the glue including also a filler comprising an amylaceous plywood glue filler used in the amount of from 30 to 300 parts for each 100 parts of the mixture of resin and spent liquor, the glue containing from 0.2 to 4.0% by weight ammonium ion (expressed as NH 3 ) on a spent liquor solids basis, the spent liquor component of the mixture prior to mixing having a pH of from 3-9, the urea formaldehyde resin component of the mixture prior to mixing being characterized by a mol ratio of formaldehyde to urea of from 1.2 to 2.5; a pH of from 6 to 9; and a methylol content corresponding to a Witte number of from 1.0 to 2.2.
Claim 3
Dependent Claim
40 words
The plywood glue of claim 1 wherein the urea formaldehyde resin is used in an amount of from 50-75 parts, the spent liquor in an amount of from 25-50 parts, and the filler in an amount of from 75-150 parts.
Claim 4
Dependent Claim
39 words
The plywood glue of claim 1 wherein the amylaceous filler comprises a cereal flour type plywood glue filler and not more than 75% by weight, based on the total weight of the filler, of a non-amylaceous plywood glue filler.
Claim 5
Dependent Claim
18 words
The plywood glue of claim 1 wherein the amylaceous filler comprises a cereal type plywood glue flour filler.
Claim 6
Dependent Claim
15 words
The plywood glue of claim 1 wherein the amylaceous filler comprises a wheat flour filler.
Claim 7
Dependent Claim
15 words
The plywood glue of claim 1 wherein the amylaceous filler comprises a sorghum flour filler.
Claim 8
Dependent Claim
18 words
The plywood glue of claim 1 wherein the amylaceous filler comprises a root starch type plywood glue filler.
Claim 9
Dependent Claim
15 words
The plywood glue of claim 1 wherein the amylaceous filler comprises a potato starch filler.
Claim 10
Dependent Claim
15 words
The plywood glue of claim 1 wherein the amylaceous filler comprises a tapioca starch filler.
Claim 11
Independent Claim
182 words
The method of making plywood which comprises applying to the surfaces of wood veneers a bonding quantity of an aqueous plywood glue comprising in admixture with each other and in parts by weight, dry solids basis: Urea-Formaldehyde Resin--30-90 Spent Liquor from the Acid Sulfite Pulping of Lignocellulose--10-70 the glue including also a filler comprising an amylaceous plywood glue filler used in the amount of from 30 to 300 parts for each 100 parts of the mixture of resin and spent liquor, the glue containing from 0.2 to 4.0% by weight ammonium ion (expressed as NH 3 ) on a spent liquor solids basis. the spent liquor component of the mixture prior to mixing having a pH of from 3-9, the urea formaldehyde resin component of the mixture prior to mixing being characterized by a mol ratio of formaldehyde to urea of from 1.2 to 2.5; a pH of from 6 to 9; and a methylol content corresponding to a Witte number of from 1.0 to 2.2, assembling the resulting glue-coated wood veneers and pressing the veneers to form the finished plywood product.
Claim 12
Independent Claim
182 words
The method of making plywood which comprises applying to the surfaces of wood veneers a bonding quantity of an aqueous plywood glue comprising in admixture with each other and in parts by weight, dry solids basis: Urea-Formaldehyde Resin--30-90 Spent Liquor from the Acid Sulfite Pulping of Lignocellulose--10-70 the glue including also a filler comprising an amylaceous plywood glue filler used in the amount of from 30 to 300 parts for each 100 parts of the mixture of resin and spent liquor, the glue containing from 0.2 to 4.0% by weight ammonium ion (expressed as NH 3 ) on a spent liquor solids basis. the spent liquor component of the mixture prior to mixing having a pH of from 3-9, the urea formaldehyde resin component of the mixture prior to mixing being characterized by a mol ratio of formaldehyde to urea of from 1.2 to 2.5; a pH of from 6 to 9; and a methylol content corresponding to a Witte number of from 1.0 to 2.2, assembling the resulting glue-coated wood veneers and pressing the veneers to form the finished plywood product.
Claim 13
Dependent Claim
10 words
The plywood product produced by the method of claim 10.
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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) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |