US3963650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making improved urea/formaldehyde foams
Assignee: British Industrial Plastics Ltd
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Filing: 1974-09-04
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Granted: 1976-06-15
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Expires: 1994-09-04
Abstract
Abstract Improved low-density, self-sustaining urea/formaldehyde foams are prepared by separate foaming of an aqueous solution of a urea/formaldehyde resin and a foaming agent to form a first foam, and foaming an aqueous solution of a hardener and a foaming agent to form a second foam, and mixing the two foams in a liquid feed ratio of resin to hardener of at least 4:1 according to the disclosed process. The resin feed may be preheated prior to foaming. Using resins of high solids content produces foams of relatively low density.
Inventors
- 👤 Dennis Henry Ogden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:55
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/30; B; B29; B29B; B29B7/00; B29B7/74; B29B7/7404; B29B7/7409; B29B7/7419; C08J2361/00; C08J2361/20; C08J2361/22; C08J2361/24; Y; Y10; Y10S; Y10S521/00; Y10S521/917
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
98 words
A method of producing a low-density, self-sustaining urea/formaldehyde foam comprising foaming a mixture including an aqueous solution of thermosetting material comprising a urea/formaldehyde resin having a theoretical solids content of at least 40% and less than about 60% and a foaming agent to produce a first foam; foaming a mixture including an aqueous solution of a hardener for the resin and a foaming agent to form a second foam; and mixing the first foam with the second foam so that the liquid feed ratio of resin to hardener is from about 4:1 up to at most about 50:1.
Claim 2
Independent Claim
98 words
A method of producing a low-density, self-sustaining urea/formaldehyde foam comprising foaming a mixture including an aqueous solution of thermosetting material comprising a urea/formaldehyde resin having a theoretical solids content of at least 40% and less than about 60% and a foaming agent to produce a first foam; foaming a mixture including an aqueous solution of a hardener for the resin and a foaming agent to form a second foam; and mixing the first foam with the second foam so that the liquid feed ratio of resin to hardener is from about 4:1 up to at most about 50:1.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein the mixture forming the first foam is heated.
Claim 4
Dependent Claim
16 words
A method according to claim 2, wherein the mixture forming the second foam is also heated.
Claim 5
Dependent Claim
14 words
A method according to claim 1, wherein the resin is a simple urea/formaldehyde resin.
Claim 6
Dependent Claim
13 words
A method according to claim 1, wherein the resin is modified urea/formaldehyde resin.
Claim 7
Independent Claim
104 words
A method of producing a low-density, high compressive strength self-sustaining urea/formaldehyde foam comprising optionally pre-heating then foaming a mixture including an aqueous solution of a thermosetting material comprising a urea/formaldehyde resin having a theoretical solids content of at least 60% and less than about 75% and a foaming agent to produce a first foam, foaming a mixture including aqueous solution of a hardener for the resin and a foaming agent to produce a second foam, and mixing the first foam with the second foam so that the liquid feed ratio of resin to hardener is from about 7:1 up to at most about 50:1.
Claim 8
Independent Claim
104 words
A method of producing a low-density, high compressive strength self-sustaining urea/formaldehyde foam comprising optionally pre-heating then foaming a mixture including an aqueous solution of a thermosetting material comprising a urea/formaldehyde resin having a theoretical solids content of at least 60% and less than about 75% and a foaming agent to produce a first foam, foaming a mixture including aqueous solution of a hardener for the resin and a foaming agent to produce a second foam, and mixing the first foam with the second foam so that the liquid feed ratio of resin to hardener is from about 7:1 up to at most about 50:1.
Claim 9
Dependent Claim
15 words
A method according to claim 6, wherein the mixture forming the first foam is heated.
Claim 10
Dependent Claim
16 words
A method according to claim 7, wherein the mixture forming the second foam is also heated.
Claim 11
Dependent Claim
14 words
A method according to claim 6, wherein the resin is a simple urea/formaldehyde resin.
Claim 12
Dependent Claim
13 words
A method according to claim 6, wherein the resin is modified urea/formaldehyde resin.
Claim 13
Independent Claim
98 words
A method of producing a low-density, high compressive stength sustaining urea/formaldehyde foam comprising heating then foaming a mixture including an aqueous solution of thermosetting material comprising a urea/formaldehyde resin having a theoretical solids content of at least 75% and a foaming agent to produce a first foam; foaming a mixture including an aqueous solution of a hardener for the resin and a foaming agent to form a second foam; and mixing the first foam with the second foam so that the liquid feed ratio of resin to hardener is from about 4:1 up to at most about 50:1.
Claim 14
Independent Claim
98 words
A method of producing a low-density, high compressive stength sustaining urea/formaldehyde foam comprising heating then foaming a mixture including an aqueous solution of thermosetting material comprising a urea/formaldehyde resin having a theoretical solids content of at least 75% and a foaming agent to produce a first foam; foaming a mixture including an aqueous solution of a hardener for the resin and a foaming agent to form a second foam; and mixing the first foam with the second foam so that the liquid feed ratio of resin to hardener is from about 4:1 up to at most about 50:1.
Claim 15
Dependent Claim
16 words
A method according to claim 11, wherein the mixture forming the second foam is also heated.
Claim 16
Dependent Claim
14 words
A method according to claim 11, wherein the resin is a simple urea/formaldehyde resin.
Claim 17
Dependent Claim
13 words
A method according to claim 11, wherein the resin is modified urea/formaldehyde resin.
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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) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |