Patent US4032515A successfully refreshed from Google Patents.
US4032515A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Curable resorcinol terminated urea-formaldehyde resins
Assignee: Beazer East Inc
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Filing: 1975-07-24
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Granted: 1977-06-28
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Expires: 1995-07-24
Abstract
Abstract A urea-formaldehyde resin based adhesive that is resistant to heat and hydrolysis and hence is useful for exterior use in plywood and laminated timbers consists of a resorcinol terminated urea-formaldehyde resin having the general formula: ##STR1## where η = 0 to 10, that is cured by conventional hardeners under neutral or alkaline conditions.
Inventors
- 👤 Elizabeth A. Blommers
- 👤 Roy H. Moult
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:12
CPC Classifications
C; C08; C08J; C08J3/00; C08G; C08G14/00; C08G14/02; C08G14/04; C08G14/06; C08G14/08; C08J2361/00; C08J2361/34
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
34 words
An adhesive comprising a resorcinol terminated urea-formaldehyde resin having the general formula: ##STR5## where η = 0 to 10, said resin being cured under neutral or alkaline conditions by reacting it with a formaldehyde.
Claim 2
Dependent Claim
34 words
An adhesive comprising a resorcinol terminated urea-formaldehyde resin having the general formula: ##STR5## where η = 0 to 10, said resin being cured under neutral or alkaline conditions by reacting it with a formaldehyde.
Claim 3
Dependent Claim
17 words
An adhesive as set forth in claim 1 wherein said resin is a sulfite-modified resorcinol terminated urea-formaldehyde.
Claim 4
Dependent Claim
13 words
An adhesive as set forth in claim 1 wherein said formaldehyde is paraformaldehyde.
Claim 5
Dependent Claim
95 words
In a method for forming an adhesive composition in which a compound of urea and formaldehyde is formed to a pH of about 8 and is polymerized to form a urea-formaldehyde resin under acid conditions of pH between about 3 and 4, the steps comprising: forming terminal methylol groups on the said resin under alkaline conditions, substituting terminal resorcinol groups for the hydroxyl radicals at a temperature of at most about 50° C. and at a pH no greater than 4, and cross-linking the so-formed resorcinol-terminated urea-formaldehyde resin at a pH of at least 7.
Claim 6
Dependent Claim
95 words
In a method for forming an adhesive composition in which a compound of urea and formaldehyde is formed to a pH of about 8 and is polymerized to form a urea-formaldehyde resin under acid conditions of pH between about 3 and 4, the steps comprising: forming terminal methylol groups on the said resin under alkaline conditions, substituting terminal resorcinol groups for the hydroxyl radicals at a temperature of at most about 50° C. and at a pH no greater than 4, and cross-linking the so-formed resorcinol-terminated urea-formaldehyde resin at a pH of at least 7.
Claim 7
Dependent Claim
27 words
The method of claim 4 in which the terminal resorcinol is added in a molar ratio to the originally employed urea of greater than 0.5 to 1.
Claim 8
Dependent Claim
29 words
The method of claim 4 in which the urea-formaldehyde resin is formed in a ratio of urea to formaldehyde of between about 1 to 2 and 1 to 1.
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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) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |