Claims
- 1. Microcomposite powder comprising:
graphite flakes (GLP) having sides from 50 to 1000 μm and a thickness from 5 to 50 μm, consisting of agglomerates of more elementary graphite particles joined together and superimposed so that their principal planes are mutually parallel; said flakes being covered with particles of a fluoropolymer from 0.1 to 0.5 μm in size.
- 2. Powder according to claim 1, further comprising a natural or synthetic graphite (G1) of lamellar shape having a particle size of 10 μm to 600 μm, said graphite (G1) being covered with particles of a fluoropolymer from 0.1 to 0.5 μm in size.
- 3. Powder according to claim 2, in which the size of the (G1) particles is between 10 and 150 μm.
- 4. Powder according to claim 1, comprising at least one other electrically conductive element covered with particles of a fluoropolymer from 0.1 to 0.5 μm in size.
- 5. Powder according to claim 1, in which the fluoropolymer is a PVDF (polyvinylidene fluoride) homopolymer or copolymer containing at least 60 wt % VF2.
- 6. Powder according to claim 1, in which the graphite flakes (GLP) consist of elementary expanded graphite flakes having sides from 5 to 20 μm and a thickness from 0.1 to 5 μm.
- 7. Powder according to claim 1, in which the proportions are, by weight, from 10 to 40% of fluoropolymer per 90 to 60%, respectively, of flakes (GLP) and, optionally, of graphite (G1) and of another electrically conductive product.
- 8. Powder according to claim 7, in which the powder comprises 15 to 30% of fluoropolymer per 85 to 70%, respectively, of flakes (GLP) and, optionally, of graphite (G1) and of another electrically conductive product.
- 9. Powder according to any one of the preceding claims claim 1, also containing further comprising up to five parts by weight of a pore-forming agent per 100 parts of the assembly consisting of the fluoropolymer, the flakes (GLP) and, optionally, the graphite (G1) and another electrical conductor.
- 10. Objects obtained by extruding or injection moulding the powder of claim 1.
- 11. Objects according to claim 10 which are bipolar plates for fuel cells, supercapacitor elements or exchange surfaces in heat exchangers.
- 12. Process for preparing the powder of any one of claims 1 to 11claim 1 by (co)atomization of one or more aqueous emulsions or dispersions containing its various constituents.
Priority Claims (1)
Number |
Date |
Country |
Kind |
02/00374 |
Jan 2002 |
FR |
|
Parent Case Info
[0001] This application claims benefit, under U.S.C. §119 or §365 of French Application Number 02/00374, filed Jan. 14, 2002; and PCT/FR02/04569 filed Dec. 27, 2002.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/FR02/04569 |
12/27/2002 |
WO |
|