Patent US3658638A successfully refreshed from Google Patents.
US3658638A
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US
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Plywood process and product wherein the adhesive comprises a lignosulfonate-phenol-formaldehyde reaction product
Assignee: Georgia-Pacific LLC
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Filing: 1970-12-02
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Granted: 1972-04-25
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Expires: 1990-12-02
Abstract
Abstract An adhesive resin composition prepared by pre-reacting lignosulfonate with phenol under alkaline conditions and subsequently reacting the lignosulfonate-phenol product with formaldehyde under alkaline conditions.
Inventors
- 👤 Charles H Ludwig
- 👤 Albert W Stout
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:27
CPC Classifications
C; C09; C09J; C09J161/00; C09J161/04; C09J161/06; C08; C08G; C08G8/00; C08G8/38; C09J197/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31942; Y10T428/31949; Y10T428/31957; Y10T428/3196
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
15 words
A process according to claim 1 wherein the alkali metal lignosulfonate is a sodium lignosulfonate.
Claim 2
Dependent Claim
68 words
A process according to claim 2 wherein the sodium lignosulfonate is reacted with the phenol until at least 10 weight percent of phenol, based upon the lignosulfonate solids, has reacted with the lignoSulfonate and the lignosulfonate-phenol product is reacted with formaldehyde in the presence of from 17 to 20 weight percent of sodium hydroxide until the gel time is in the range of from 26 to 28 minutes.
Claim 3
Dependent Claim
18 words
A process according to claim 3 wherein the sodium lignosulfonate is a sodium salt of spent sulfite liquor.
Claim 4
Dependent Claim
63 words
A process according to claim 2 wherein the sodium lignosulfonate and phenol are reacted in the presence of an alkali metal hydroxide for up to 24 hours at a temperature in the range of 90* to 180* C at a pH in the range of from 9 to 12 in an aqueous medium having solids concentration of from 35 to 90 weight percent.
Claim 5
Dependent Claim
77 words
A process according to claim 5 wherein the sodium lignosulfonate in an amount of from 25 to 50 weight percent, based upon the phenol, is intermixed with the phenol at a pH in the range of from 9.5 to 11 in an aqueous medium having a solids concentration in the range of from 65 to 85 weight percent and reacted at a temperature in the range of 90* to 125* C for from one to 4 hours.
Claim 6
Dependent Claim
40 words
A process according to claim 6 wherein the lignosulfonate-phenol product is reacted with formaldehyde in the presence of from 17 to 20 weight percent of sodium hydroxide until the gel time is in the range of 26 to 28 minutes.
Claim 7
Dependent Claim
18 words
A process according to claim 7 wherein the sodium lignosulfonate is a sodium salt of spent sulfite liquor.
Claim 8
Dependent Claim
10 words
A plywood panel obtained by the process of claim 1.
Claim 9
Dependent Claim
10 words
A plywood panel obtained by the process of claim 3.
Claim 10
Dependent Claim
10 words
A plywood panel obtained by the process of claim 7.
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |