| 摘要 |
PURPOSE:To restrain a thermal sticking phenomenon from occurring and contrive higher printing quality, by controlling the surface ruggedness and surface roughness of one side of a base film for a thermal transfer ribbon to predetermined values. CONSTITUTION:Recesses and projections on at least one side of a thermoplastic resin film are so made that the density rho1 of the recesses and projections with a diameter phiof at least 1mum and less than 5mum is in the range of 40<=rho1<=200, and the density rho2 of the recesses and projections with a diameter phi of at least 0.5mum and less than 1mum is in the range of 400<=rho2<=2,000 (unit: pieces/0.01mm<2>). The average height of the projections on the film surface is 0.10-0.50mum. With the film surface provided with the recess-projection characteristics defined by the above average projection height and the above density of the recesses and projections, a thermoplastic resin film bent suited to a base film for a thermal transfer ribbon can be obtained. When the properties are below the lower limits of the above conditions, thermal sticking occurs between a thermal head and the film, whereas when the properties are above the upper limits of the conditions, the thermal sticking is prevented but the contact of the head and the film becomes unsatisfactory, resulting in that thermally transferred images are obscure. |
