▎ 摘　　要

NOVELTY - Water-soluble carbon ink comprises carbon-type conductor powder, thickener, stabilizer, auxiliary agent, 20-30 wt.% water-soluble urethane resin, 2-10 wt.% urethane curing agent and 20-80 wt.% water. The carbon-type conductor powder includes 2-15 wt.% conductive carbon and 5-20 wt.% impression graphite. USE - The water-soluble carbon ink is useful for surface heating device (claimed). ADVANTAGE - The water-soluble carbon ink can be prepared using water without using organic solvent, has improved conductivity and adhesion which can be issued during product processing, and/or electrical short-circuit caused by dropout phenomenon due to bending or bending during construction of the finished product, harmless to the human body, prevents deterioration of durability due to spark generation and/or resistance value change, and is environmentally friendly. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for surface heating device comprising a sheet (10), a carbon wire (20) coated on the sheet, a first metal film (30) parallel to both ends of the carbon wire, and a second metal film (40) in contact with the first metal film and spaced apart from the carbon wire. The carbon wire comprises conductive carbon, impression graphite, and epoxide-based compound of formula (I). R1 = C=C-COOH, or C=C-OCOCH3; and R2-R4 = CH3. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the surface heating device. Sheet (10) Carbon wire (20) First metal film (30) First upper metal film (31) Second metal film (40)