As a device for forming a print on a transfer receiving article without being restricted, as proposed in Patent Literature 1, an intermediate transfer medium in which a transfer layer including a receiving layer (hereinbelow, this layer may be referred to as a transfer layer) is peelably provided on a substrate has been used. According to this intermediate transfer medium, a print where a thermally transferable image has been formed on an optional transfer receiving article can be obtained by forming the thermally transferable image on the receiving layer of the intermediate transfer medium by means of a thermal transfer sheet having a colorant layer, and then transferring the transfer layer which includes this receiving layer onto the optional transfer receiving article. Particularly, an intermediate transfer medium is particularly preferably used for transfer receiving articles onto which colorants are less likely to transfer and thus which cannot form a high-quality image directly thereon, transfer receiving articles which easily fuse with a colorant layer on thermal transfer, and the like.
Incidentally, depending on the type of a print obtained by transferring the transfer layer of the intermediate transfer medium on a transfer receiving article, it may be necessary to leave a certain region untreated, for instance, regions allocated for an IC chip, a magnetic strip, a transmitting and receiving antenna unit, a signature portion and the like. Thus, on the surface of the transfer receiving article, in some cases, there is a region that is inconvenient when covered with the transfer layer. In other words, there may be some cases where the surface of a transfer receiving article is required to be exposed.
Under these circumstances, some attempts have been made, wherein, by using a thermal transfer sheet in which a peel-off layer is provided on one surface of a substrate, in advance of transferring the transfer layer of an intermediate transfer medium onto a transfer receiving article, a portion of the transfer layer, for example, a region of the transfer layer which is not desired to be transferred onto the transfer receiving article is removed (it may be also referred to as “peeled off”) by means of the peel-off layer in advance. For example, Patent Literature 2 proposes a method in which, after the peel-off layer of a thermal transfer sheet and the transfer layer of an intermediate transfer medium are superposed on each other so as to become in contact with each other, energy is applied to the other surface of the substrate of the heat transfer sheet, and the transfer layer corresponding to the region to which the energy has been applied is removed by means of the peel-off layer.
As one of problems that may occur when a portion of the transfer layer of the intermediate transfer medium is removed by means of the peel-off layer of the above-described thermal transfer sheet, a problem that the peel-off layer, which naturally should remain together with the transfer layer that has been removed on the side of the thermal transfer sheet, transfers to the side of the intermediate transfer medium (so called reverse transfer of the peel-off layer) can be included. Reverse transfer of the peel-off layer tends to occur in the case where adhesiveness between the substrate and the peel-off layer (it may be also referred to as an adhesive property) is low. Under these circumstances, for example, in Patent Literature 2 described above, an embodiment in which the adhesiveness between the substrate and the peel-off layer has been improved by using a substrate subjected to easily-adhesive treatment is proposed although no attention is paid to reverse transfer of the peel-off layer.
However, responding to a recent demand for accelerating printers, the energy to be applied to the thermal transfer sheet tends to increase when the transfer layer of an intermediate transfer medium is removed by means of a peel-off layer. In the case where, as the transfer layer of the intermediate transfer medium, a layer having high durability, for example, a thick transfer layer is used, the transfer layer becomes difficult to remove unless the energy to be applied to the thermal transfer sheet is increased. As for thermal transfer sheets having a peel-off layer proposed up to now, the measure in the case where the energy to be applied to the thermal transfer sheet is increased on removal of a portion of the transfer layer is not sufficient. Under the current circumstances, reverse transfer of the peel-off layer cannot be sufficiently inhibited when high energy is applied to the thermal transfer sheet to remove a portion of the transfer layer of the intermediate transfer medium.