Hexcel Corporation

Frank W Lee

Kenneth S Baron

Yen-Seine Wang

Ching-Chi Kuo

Susan M Brinkerhoff

Stella M McKinney

Maureen Boyle

Ken Baron

David B Conway

Jon D Neuner

High strength foam-filled materials and methods for their production are disclosed. The high strength materials include cellular structures comprising a plurality of open-ended cells containing polycyanurate foam. The polycyanurate foam-filled cellular structures have synergistically high mechanical properties and improved resistance to moisture. When cyanate ester foamable precursors in the form of tough films are foamed to fill honeycomb cells, the resulting foam-filled honeycomb has uniformly fine foam cell structure and improved bonding between the foam and the honeycomb.

Foam filled honeycomb and methods for their production

A fiber reinforced resin matrix composite material repair system is provided, which critically employs a resin comprising a catalyst of the formula I: ##STR1## with a multifunctional epoxy resin, the resin system being sealed in a water-proofed environment prior to being coated onto a fiber reinforcement. The coated fiber reinforcement is applied over the damaged area, the damaged portion having been removed, and the surrounding surface smoothed. An adhesive is applied to the remaining surface, prior to application of the patch. The resulting patch, which may further include thermoplastic toughening agents and an enhancer, can be directly cured at temperatures below 212.degree. F. to give physical properties similar to the original material.

Low energy cured composite repair system based on imidazole-blocked

Low energy cured composite repair system based on epoxy resin with

Foamable resin compositions of cyanate esters and thermoplastic resins are disclosed.

Cyanate resin-based foams

A matrix resin system, for the preparation of composite parts, is comprised of a major amount of cyanate resin and an epoxy resin modified by reaction with an isocyanate. The resin system can be toughened by the addition of thermoplastic material, the toughness improvement being enhanced by the addition of a polyester rubber additive. The modified epoxy resin system is itself a resin having good modulus and Tg characteristics. The resin is cured at temperatures of 250.degree.-400.degree. F. in the presence of a metallic complex catalyst, and OH donor.

Toughened, high temperature resin matrix system

A composite tooling part having excellent dimensional stability, which may be prepared at low cost employs a one-component epoxy resin system having a catalyst which is the reaction product of an aromatic dicyanate and an imidazole. Reinforcing materials are incorporated in the matrix, and the resulting prepreg is allowed to cure at low temperature, down to about room temperature, until the free standing state is obtained. Thereafter, if elevated temperature performance is necessary, the product can be post-cured at elevated temperatures, without the need for a high temperature master.

Composite tooling

A latent catalyst for epoxy resin systems is produced by the reaction between an aromatic dicyanate and imidazoles. The catalyst provides good curability, excellent mechanical properties, and remarkably extended shelf life. It also allows curing at room temperature.

Modified imidazole latent epoxy resin catalysts and systems comprising

A curing agent for one package epoxy resin systems is disclosed as a imidazole blocked naphthyl diisocyanate which, when incorporated in epoxy resins, has an extended shelf life and can be cured by exposure to relatively low temperatures. The curing agent is insoluble in epoxy resins that are liquid at room temperature and is useful in connection therewith.

Growing community of inventors

Danville, CA, United States of America

Frank W Lee