| 摘要 |
<p>A thermal transfer ink sheet composed of a substrate, a thermal transfer ink layer formed on one side of the substrate, and a back coat layer formed on the other side of the substrate, characterized in that the back coat layer has a kinetic friction coefficient smaller than 0.25 (with respect to the thermal head) which varies depending on whether printing is going on or not, such that it has a value of mu 1 when printing is going on and a value of mu 2 when printing is not going on, with the ratio of mu 1/ mu 2 being from 0.8 to 1.2. The kinetic friction coefficient in the specified range can be obtained by employing a slip agent which does not greatly change the kinetic friction coefficient of the back coat layer depending on whether printing is going on or not, or by employing two slip agents in combination, one giving the back coat layer a kinetic friction coefficient which is higher when printing is going on than when printing is not going on, the other giving the back coat layer a kinetic friction coefficient which is lower when printing is going on than when printing is not going on. The thermal transfer ink sheet runs smoothly without imposing unnecessary loads to the thermal head and hence gives rise to a high-quality print image free of printing pitch fluctuation. <IMAGE></p> |
