Thermal transfer recording medium including base material layer, welding layer, first thermal transfer layer, and second thermal transfer layer, printing device, and cassette accommodating thermal transfer recording medium

A thermal transfer recording medium comprising:

• a base material layer having a first surface and a second surface;
• and
• a welding layer;
• a first thermal transfer layer;
• and
• a second thermal transfer layer, the welding layer, the first thermal transfer layer, and the second thermal transfer layer being in direct contact with each other and being laminated in this order on the first surface of the base material layer,
• wherein when the thermal transfer recording medium is heated at a low temperature higher than or equal to a first temperature and lower than or equal to a second temperature, a bonding strength between the welding layer and the first thermal transfer layer is greater than a bonding strength between the first thermal transfer layer and the second thermal transfer layer, and
• wherein when the thermal transfer recording medium is heated at a high temperature higher than the second temperature, the bonding strength between the first thermal transfer layer and the second thermal transfer layer is greater than a bonding strength between the base material layer and the first thermal transfer layer.

A thermal transfer recording medium comprising:

• a base material layer;
• a welding layer containing a welding material;
• a first ink layer containing first ink;
• and
• a second ink layer containing second ink, the base material layer, the welding layer, the first thermal transfer layer, and the second thermal transfer layer being laminated in this order, at least a portion of the first ink layer and the second ink layer being configured to be thermally transferred onto a printing medium,
• wherein when external forces are applied to both the base material layer and the second ink layer in directions away from each other in a first state, a breakage occurs between the first ink layer and the second ink layer or within the second ink layer, the first state being a state in which the thermal transfer recording medium has been heated to a temperature higher than or equal to a first temperature and lower than or equal to a second temperature and subsequently cooled to a temperature lower than or equal to a third temperature,
• wherein when the external forces are applied in a second state, a breakage occurs between the first ink layer and the base material layer or within the first ink layer, the second state being a state in which the thermal transfer recording medium has been heated to a temperature higher than the second temperature and subsequently cooled to a temperature lower than or equal to the third temperature.

A printing device configured perform:

• a heating process heating a thermal transfer recording medium in a state where the thermal transfer recording medium is in contact with a printing medium, the thermal transfer recording medium including:
• a base material layer;
• a first ink layer containing first ink;
• and a second ink layer containing second ink, the base material layer, the first ink layer, and the second ink layer being laminated in this order;
• a cooling process cooling the thermal transfer recording medium heated in the heating process;
• and
• a transfer process transferring at least part of the first ink and the second ink onto the printing medium by applying external forces to both the base material layer and the second ink layer of the thermal transfer recording medium cooled in the cooling process in directions away from each other,
• wherein in the heating process and the cooling process:
• the printing device heats a first portion of the thermal transfer recording medium to a temperature higher than or equal to a first temperature and lower than or equal to a second temperature and subsequently cools the first portion to a temperature lower than or equal to a third temperature to place the first portion in a first state, and the printing device heats a second portion of the thermal transfer recording medium to a temperature higher than the second temperature and subsequently cools the second portion to a temperature lower than or equal to the third temperature to place the second portion in a second state,
• wherein in the transfer process:
• the printing device applies the external forces to break the thermal transfer recording medium between the first ink layer and the second ink layer or within the second ink layer at the first portion of the thermal transfer recording medium and transfer the second ink onto the printing medium;
• and
• the printing device applies the external forces to break the thermal transfer recording medium between the first ink layer and the base material layer or within the first ink layer at the second portion of the thermal transfer recording medium and transfer the first ink and the second ink onto the printing medium.

A cassette accommodating therein:

• a thermal transfer recording medium comprising:
• a base material layer having a first surface and a second surface;
• a welding layer;
• a first thermal transfer layer;
• and
• a second thermal transfer layer;
• and
• a printing medium onto which a portion of the thermal transfer recording medium is to be thermally transferred,
• wherein in the thermal transfer recording medium, the welding layer, the first thermal transfer layer, and the second thermal transfer layer are in direct contact with each other and are laminated in this order on the first surface of the base material layer, and
• wherein the welding layer has a solubility parameter higher than a solubility parameter of each of the base material layer and the first thermal transfer layer.