Prepregs comprising a fibrous base with a first coating of C-stage thermosetting resin and an outer second coating of B-stage thermosetting resin and a method of making the same
AssigneeIsovolta Osterreichische Isolierstoffwerke Aktiengesellschaft
InventorsBela Zimics, Willibald Orthofer
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Abstract
The invention concerns a compressible prepreg based on flat substrates impregnated with thermosetting synthetic resins, characterized in that it comprises a first, C stage synthetic-resin layer directly deposited on the substrate and a second, B stage synthetic-resin layer deposited on the first synthetic-resin layer.
Claims14
A compressible prepreg based on flat substrates comprising webs or fabrics of organic or inorganic fiber impregnated with thermosetting synthetic resins comprising epoxy resins or polyester resins, said prepreg comprising a first layer of said synthetic resin in the C stage directly deposited on the substrate and a second layer of said synthetic resin in the B stage directly deposited on the first layer of synthetic resin.
A method of making a compressible prepreg comprising:
- i) impregnating a flat substrate comprised of a web or fabric of organic or inorganic fibers, with a first thermosetting synthetic resin comprised of an epoxy or polyester resin;
- ii) heating said impregnated substrate to convert said first thermosetting synthetic resin to the C stage;
- iii) applying a second thermosetting synthetic resin comprised of an epoxy or polyester resin, to said impregnated substrate;
- and
- iv) heating said second thermosetting resin to convert it to the B stage.
A method of making electrically insulated metal windings for electrical machinery comprising:
- a) contacting a compressible prepreg with a metal strip under tension to form a metal-prepreg winding, said compressible prepreg being formed by:
- i) impregnating a flat substrate comprised of a web or fabric of organic or inorganic fibers, with a first thermosetting synthetic resin;
- ii) heating said impregnated substrate to convert said first thermosetting synthetic resin to the C stage;
- iii) applying a second thermosetting synthetic resin to said impregnated substrate;
- and
- iv) heating said second thermosetting synthetic resin to convert it to the B stage;
- and
- b) heating the metal-prepreg winding to convert said second thermosetting synthetic resin from the B stage to the C stage.
Dependencies are inferred from the claim text.