Sized carbon fibers capable of use with polyimide matrix
US4394467A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1981 |
| Grant date | Jul 19, 1983 |
| Priority date | — |
| Expiry date | Jun 22, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31721
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Carbon fibers are provided which bear an improved finish coating upon the surface which is capable of withstanding the high temperatures (e.g., above 500.degree. F.) commonly encountered during the formation of composite structures employing a polyimide matrix. The sized carbon fibers prior to the curing to form a rigid polyimide coating are flexible, may be readily handled without significant damage, and are amenable to good impregnation with the matrix resin thereby facilitating the formation of quality composite structures. The finish comprises a mixture of selected precursors for the formation of a rigid polyimide (as described). More specifically, the size composition is formed from at least one aromatic diamine, at least one aromatic dianhydride, and at least one aromatic tetracarboxylic acid diester. A film-forming polyamic acid oligomer readily forms and is present as an intermediate reaction product within the finish coating and the aromatic tetracarboxylic acid diester has been found to beneficially serve primarily as a flexibility preserving diluent during the early stages of the polyimide-forming reaction which takes place within the finish coating. The finish is fully …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.