Abstract: A heat-dissipating black resin composition having excellent physical properties such as heat-dissipation, workability, corrosion resistance, solvent resistance, coating adherence and gloss, and being free from chromium and used for surface treatment of a zinc coated steel sheet and a zinc coated steel sheet treated thereby. The composition includes, based on 100 parts by weight: 10 to 60 parts by weight of a resin composition which at least one main resin and a melamine-based curing agent are mixed in a weight ratio of 10:2-7, the main resin being selected from the group consisting of polyester, epoxy, polyolefin, polyurethane, fluorine, phenol, acryl and polycarbonate resins; 1 to 10 parts by weight of at least one pigment selected from the group consisting of carbon black and carbon nano tube; 1 to 10 parts by weight of a matting agent; and a solvent.

Abstract: Provided are a heat-dissipating black resin composition having excellent physical properties such as heat-dissipation, workability, corrosion resistance, solvent resistance, coating adherence and gloss, and being free from chromium and used for surface treatment of a zinc coated steel sheet, a method for treating a zinc coated steel sheet, and a zinc coated steel sheet treated thereby. The composition includes, based on 100 parts by weight: 10 to 60 parts by weight of a resin composition which at least one main resin and a melamine-based curing agent are mixed in a weight ratio of 10:2-7, the main resin being selected from the group consisting of polyester, epoxy, polyolefin, polyurethane, fluorine, phenol, acryl and polycarbonate resins; 1 to 10 parts by weight of at least one pigment selected from the group consisting of carbon black and carbon nano tube; 1 to 10 parts by weight of a matting agent; and the balance of a solvent.