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EP0441453A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Process for preparing thermoset composite articles

Assignee: Shell Internationale Research Maatschappij BV
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Filing: 1991-02-07
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Granted: —
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Expires: 2011-02-07
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Abstract

Abstract A process is described for preparing thermoset composite articles under relatively mild conditions. The process includes exposing a laminate comprising a partially-cured thermosettable resin and a fibrous substrate to an elevated temperature which increases over time, the elevated temperature being below the glass transition temperature of the resin but sufficient to promote further curing and increase the glass transition temperature thereof to the ultimate glass transition temperature of the resin. The temperature of exposure is generally increased at a rate which maintains the temperature within 20°C below the glass transition temperature of the thermosettable resin, so that cure of the resin proceeds in the glassy state. The pressure during the process is generally maintained below 3.4 atmosphere and is preferably atmospheric pressure. The process enables the production of thermoset composite articles suitable for high-performance applications without lengthy autoclave treatments.

Inventors

  • 👤 Walter Vay Breitigam
  • 👤 Ronald Sherman Bauer
  • 👤 Clayton Adam May

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-03 07:29
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/24; C08J3/244; B; B29; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/42; C08J5/00; C08J5/24; C08J5/241; C08J5/244

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 87 words
A process for preparing a thermoset composite article, the process comprising: (a) providing a laminate comprising a fibrous reinforcing agent and a partially-cured thermosettable resin system; (b) exposing said laminate, at a pressure of less than 3.4 atmosphere, to an elevated temperature which elevated temperature increases over time in a way so that further cure of the resin system is promoted and the glass transition temperature thereof is increased, provided that said glass transition temperature remains below the ultimate glass transition temperature of the thermosettable resin system.
Claim 2
Dependent Claim 28 words
A process according to claim 1 in which the temperature of exposure of the laminate remains within 20°C below the glass transition temperature of the thermosettable resin system.
Claim 3
Dependent Claim 22 words
A process according to claim 1 or 2 in which the thermosettable resin system comprises an epoxy resin and a curing agent.
Claim 4
Dependent Claim 25 words
A process according to any one of claims 1 to 3 in which the thermosettable resin comprises a diglycidyl ether of a bisphenol of fluorene.
Claim 5
Dependent Claim 21 words
A process according to any one of claims 1 to 4 in which step (b) is carried out at atmospheric pressure.
Claim 6
Dependent Claim 25 words
A process according to any one of claims 1 to 5 in which step (b) is carried out in a series of ramped heating stages.
Claim 7
Dependent Claim 27 words
A process according to any one of claims 1 to 6 in which the laminate comprises a set of layered prepregs and is in a consolidated state.
Claim 8
Dependent Claim 33 words
A process according to any one of claims 1 to 7 in which the temperature of step (b) is increased at a rate within the range of from 0.1 to 2°C per minute.
Claim 9
Dependent Claim 81 words
A process according to any one of claims 1 to 8 in which the time of exposure of the laminate according to step (b) is within the range of from one hour to three hours. 10. A process according to any one of claims 1 to 9 which further comprises exposing, at atmospheric pressure, the laminate cured according to seep (b) to a temperature at or near its ultimate glass transition temperature for a time of up to about ten hours.

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