| 摘要 |
PURPOSE:To extremely effectively improve coating propriety of a base sheet and to improve recording sensitivity for an ultrahigh speed machine by adjusting leakage propriety of the sheet and smoothness of its surface obtained by mixing regenerated pulp to specific ranges based on a certain special measuring method. CONSTITUTION:A base sheet in which 3wt.% or more of regenerated pulp obtained by deinking including a mechanically agitating step for applying compression force to waste sheet in the presence of deinking agent of surfactant, etc., is contained in entire pulp composition, its dynamic leakage value is -0.32 - +0.15g/m<2>, and a measured value by a surface normal reflection type smoothness meter is 12% or more under pressurizing condition of 20kg/cm<2> or less, is used. Its dynamic leakage value is adjusted to fall within a range of -0.32 - +0.15g/m<2>, more desirably -0.30 - +0.10g/m<2>. If the value exceeds +0.15g/m<2>, formation of smoothly coating surface becomes difficult, and a heat sensitive recording layer is reduced in thickness. However, if it becomes -0.32g/m<2> or smaller, its step coverage is reduced. Accordingly, in both cases, the sheet having desired recording sensitivity cannot be obtained. |
