Patent ID: 8343889

Claim:
A thermal transfer sheet comprising: a substrate; a heat resistant slip layer provided on one side of the substrate; an undercoat layer and a dye layer provided in that order on the other side of the substrate, wherein the undercoat layer is formed by applying and drying a coating liquid which contains, as main components, a water soluble self cross-linking resin and colloidal inorganic pigment ultrafine particles, and cross-linking polymerizing the water soluble self cross-linking resin; wherein the total amount of the water soluble self cross-linking resin and colloidal inorganic pigment ultrafine particles is 95% by weight or more of a solid content of the undercoat layer; and wherein the solid content ratio by weight of the colloidal inorganic pigment ultrafine particles to the water soluble self cross-linking resin is 1/1 to 1/0.05.