US4026980A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing moulded expanded urea formaldehyde products
Assignee: Imperial Chemical Industries Ltd
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Filing: 1974-07-30
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Granted: 1977-05-31
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Expires: 1994-07-30
Abstract
Abstract Expanded urea formaldehyde products are moulded from urea formaldehyde resin solution, a catalyst such as formic acid and, optionally, a foaming agent, casting the mixture in an open-topped mould, partially drying and curing the resulting gel at 20 DEG C to 70 DEG C to produce a preform, and subsequently heat-treating the preform above 120 DEG C in a restraining mould and allowing it to expand therein.
Inventors
- 👤 Donald Arthur Hubbard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:32
CPC Classifications
B; B29; B29C; B29C44/00; B29B; B29B11/00; B29B11/06; B29C44/34; B29C44/36; B29C44/38; B29C44/40; C; C08; C08J; C08J9/00; C08J9/30; B29C35/00; B29C35/02; B29C35/0227; B29K; B29K2061/00; B29K2061/20; C08J2361/00; C08J2361/02; C08J2361/20; Y; Y10; Y10S; Y10S264/00; Y10S264/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
102 words
Process for producing moulded expanded urea formaldehyde products, which comprises the steps of: (a) incorporating in a urea formaldehyde resin solution a catalyst which causes gelling and curing of the resin solution, (b) depositing said mixture into an open top mould to partially fill said mould and permitting said mixture to gel, (c) partially drying and curing the resulting gel at a temperature between ambient temperature and about 70° C. to produce a preform, and subsequently (d) closing the mould and heat-treating said preform at a temperature above about 120° C. to further cure and expand said preform inside the closed mould.
Claim 2
Dependent Claim
102 words
Process for producing moulded expanded urea formaldehyde products, which comprises the steps of: (a) incorporating in a urea formaldehyde resin solution a catalyst which causes gelling and curing of the resin solution, (b) depositing said mixture into an open top mould to partially fill said mould and permitting said mixture to gel, (c) partially drying and curing the resulting gel at a temperature between ambient temperature and about 70° C. to produce a preform, and subsequently (d) closing the mould and heat-treating said preform at a temperature above about 120° C. to further cure and expand said preform inside the closed mould.
Claim 3
Dependent Claim
17 words
Process as claimed in claim 1, wherein the urea formaldehyde resin solution also contains melamine formaldehyde resin.
Claim 4
Dependent Claim
31 words
Process as claimed in claim 1, which comprises the step of also incorporating a foaming agent in the resin solution and mechanically heating said solution to incorporate finely-divided air bubbles therein.
Claim 5
Dependent Claim
12 words
Process as claimed in claim 1, wherein the catalyst is formic acid.
Claim 6
Dependent Claim
26 words
Process as claimed in claim 1, wherein said heat treating of said preform is carried out at a temperature between about 140° C. and 155° C.
Claim 7
Dependent Claim
20 words
Process as claimed in claim 1, wherein pressure is applied to said dosed mould to ensure that it remains closed.
Claim 8
Dependent Claim
17 words
Process as claimed in claim 6, wherein the said pressure is between about 50 and 300 psi.
Claim 9
Dependent Claim
117 words
Process for producing moulded expanded urea formaldehyde products, which comprises the steps of (a) incorporating in a urea formaldehyde resin solution a catalyst which causes gelling and curing of the resin solution, (b) depositing said mixture into an open top mould and permitting said mixture to gel, (c) partially drying and curing the resulting gel at a temperature between ambient temperature and about 70° C. to produce a preform, (d) transferring said preform into a second mould having dimensions at least slightly greater than said open top mould and (e) closing said second mould and heat-treating said preform at a temperature above about 120° C. to further cure and expand said preform in said closed second mould.
Claim 10
Dependent Claim
117 words
Process for producing moulded expanded urea formaldehyde products, which comprises the steps of (a) incorporating in a urea formaldehyde resin solution a catalyst which causes gelling and curing of the resin solution, (b) depositing said mixture into an open top mould and permitting said mixture to gel, (c) partially drying and curing the resulting gel at a temperature between ambient temperature and about 70° C. to produce a preform, (d) transferring said preform into a second mould having dimensions at least slightly greater than said open top mould and (e) closing said second mould and heat-treating said preform at a temperature above about 120° C. to further cure and expand said preform in said closed second mould.
Claim 11
Dependent Claim
26 words
Process as claimed in claim 8, wherein the heat treating of said preform is carried out at a temperature between about 140° C., and 155° C.
Claim 12
Dependent Claim
31 words
Process as claimed in claim 8, which comprises the step of also incorporating a foaming agent in the resin solution and mechanically heating said solution to incorporate finely-divided air bubbles therein.
References Cited (Backward Citations)
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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) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |