| 摘要 |
PURPOSE:To obtain a heat sensitive recording material having excellent heat response for coloring in high density from a low energy range by providing an under layer which contains nonfoamable microhollow sphere having 30% or more of specific void ratio as a main ingredient with a shell of thermoplastic resin between a support and a heat sensitive coloring layer. CONSTITUTION:An underlayer which contains nonfoamable microhollow sphere having 30% or more of specific void ratio as a main ingredient with a shell of thermoplastic resin is provided between a support and a heat sensitive coloring layer. The resin of the shell includes, for example, styrene resin, styrene/ acrylic copolymer resin. The sphere made of it has excellent heat insulation and high sensitivity. The sphere having 1mum of outer diameter of particle is desirable. If it exceeds 1mum, it introduces irregularity of the underlayer and needs surface treatment such as pigment coating, and since it is bulky, there is inconvenience that its thickness is increased more than required. |
