Fibre reinforced composites
AssigneeHexcel Holding GmbH
InventorsWilhelm Pointer, Thorsten Ganglberger
Life of this patent
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Abstract
Prepregs and stacks of prepregs based on reactive epoxy resins that can be cured at lower externally applied temperatures such as from 70° C. to 110° C. with acceptably short cycle times comprise epoxy resins of epoxy equivalent weight from 200 to 500 containing a curing agent but no hardener.
Claims25
A prepreg comprising a fibrous reinforcement and a curable epoxy resin mixture comprising an epoxy resin having an epoxy equivalent weight of from 150 to 1500 and from 0.5 to 10 weight percent of a urea based curing agent, based on the total weight of said epoxy resin mixture, said urea curing agent being the only curative in said epoxy resin mixture, said epoxy resin mixture being curable by an externally applied temperature in the range of 70° C. to 110° C.
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A method for making a curable stack of prepregs, said method comprising the steps of:
- a. providing a plurality of prepregs which each comprise a fibrous reinforcement and a curable epoxy resin mixture comprising an epoxy resin having an epoxy equivalent weight of from 150 to 1500 and from 0.5 to 10 weight percent of a urea based curing agent, based on the total weight of said epoxy resin mixture, said urea curing agent being the only curative in said epoxy resin mixture, said epoxy resin mixture being curable by an externally applied temperature in the range of 70° C. to 110° C.;
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- b. stacking said prepregs on top of each other to form said curable stack of prepregs.
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Dependencies are inferred from the claim text.