Patent US4035456A successfully refreshed from Google Patents.
US4035456A
Expired / Lapsed
US
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Process for the manufacturing a cured expanded non-cracking dimensionally stable urea formaldehyde product
Assignee: Imperial Chemical Industries Ltd
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Filing: 1974-10-29
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Granted: 1977-07-12
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Expires: 1994-10-29
Abstract
Abstract A strong, expanded moulded panel or board, having a specific gravity between 0.2 and 0.8, is produced by heating dry urea formaldehyde resin containing 4% to 8% volatile materials in a mould at between 130 DEG and 160 DEG C under light restraining pressure between 30 and 300 psi which permits moderate expansion of the resin owing to the gasification of the volatile materials.
Inventors
- 👤 Donald Arthur Hubbard
- 👤 Kenneth Atkinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:23
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/24; C08J9/04; C08J9/12; C08L; C08L61/00; C08L61/20; C08L61/22; C08L61/24; C08J2361/00; Y; Y10; Y10S; Y10S264/00; Y10S264/02; Y10S264/05; Y10S264/07; Y10S264/17
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
96 words
A process for manufacturing a molded product which comprises the step of heating substantially dry, uncured urea formaldehyde resin powder, which powder contains up to 8% volatile materials, to a molding temperature above 180° C. but below the decomposition temperature of the resin, in a mold under light restraining pressure of between 5 and 500 psi so as to produce a cured expanded non-cracking and dimensionally stable molded product, wherein the powder is heated to said temperature by a rapid initial heating whereby the temperature at the end of one minute is greater than 45° C.
Claim 2
Dependent Claim
96 words
A process for manufacturing a molded product which comprises the step of heating substantially dry, uncured urea formaldehyde resin powder, which powder contains up to 8% volatile materials, to a molding temperature above 180° C. but below the decomposition temperature of the resin, in a mold under light restraining pressure of between 5 and 500 psi so as to produce a cured expanded non-cracking and dimensionally stable molded product, wherein the powder is heated to said temperature by a rapid initial heating whereby the temperature at the end of one minute is greater than 45° C.
Claim 3
Dependent Claim
21 words
The process as claimed in claim 1, wherein the average temperature at the end of 13 minutes is about 126° C.
Claim 4
Dependent Claim
22 words
A process as claimed in claim 1, wherein the temperature at the end of 14 minutes is at least about 112° C.
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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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |