Electrically conductive composition, sheet-form flexible electrode using same, and method for producing said electrode

An electrically conductive composition, comprising a thermoplastic elastomer and flaky graphite, wherein

• the thermoplastic elastomer is selected from the group consisting of styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS) and styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), wherein a styrene content in the thermoplastic elastomer is 35% by mass or less,
• a melt viscosity of the thermoplastic elastomer at 200° C. in a low shear zone with a shear rate of 60 s−1 or more and 200 s−1 or less is 50 Pa·s or more and 1400 Pa·s or less, and
• the flaky graphite has a roundness of 0.5 or less, and a volume-based particle size distribution curve of the flaky graphite has one or more peaks, and a shoulder portion continuous on a small particle size side of a main peak defined by selecting one of the peaks as the main peak, and in the volume-based particle size distribution curve, a peak top of the main peak is present at a particle size of 50 μm or more to 300 μm, and at least one of a start point and an end point of the shoulder portion is present at a particle size of 10 μm or more to 100 μm,
• wherein the electrically conductive composition is a solvent-free electrically conductive composition that is formed by kneading a raw material composition comprising the thermoplastic elastomer and expanded graphite, and the expanded graphite has a roundness of 0.5 or less before kneading, and wherein the flaky graphite is produced from the expanded graphite after kneading.