US 2004/0000735 A1 · Partially expanded, free flowing, acid treated graphite flake

Abstract

Partially expanded graphite flake having a specific volume of no more than about 50 cm3/g, more preferably, about 10-25 cm3/g has excellent sheet forming properties and is readily moldable to form molded products, such as gaskets. The partially expanded graphite flake may be produced by a low temperature process, in which the flakes are first intercalated with an intercalation solution, then subjected to a low temperature exfoliation of below about 500° C. In an alternative process, the flakes are intercalated with no more than about 40 pph of an intercalation solution (less if the particles are not subjected to a subsequent washing step) and then exfoliated at conventional exfoliation temperatures of about 800° C.

Claims21

Dependent claims

A method of forming a partially expanded graphite flake material comprising:

a) adding an amount of a liquid intercalation solution to graphite flakes, the liquid intercalation solution including one or members of the group consisting of nitric acid, sulfuric acid, acetic acid, formic acid, potassium chlorate, chromic acid, potassium permanganate, potassium chromate, potassium dichromate, perchloric acid, hydrogen peroxide, iodic acids, periodic acids, ferric chloride, and halides;
b) dispersing the intercalation solution through the graphite flakes to produce intercalated graphite flakes;
c) exfoliating the intercalated graphite flakes to produce the partially expanded graphite flake material having a low volume of no more than 50 cm3/g, the low volume being achieved by controlling at least one of:
a temperature of exfoliation;
and
the amount of the liquid intercalation solution.

3 more elements

Dependencies are inferred from the claim text.

Partially expanded, free flowing, acid treated graphite flake

Life of this patent

Partially expanded, free flowing, acid treated graphite flake

Life of this patent

Abstract

Claims21