| 摘要 |
PROBLEM TO BE SOLVED: To provide a white paperboard which is excellent in printing resistance, has a sufficient effect of preventing rule mark cracks and good color fading properties.SOLUTION: In a white paperboard, a coating layer based on a pigment and an adhesive is provided on at least one side of base paper which has a blend ratio of used paper pulp of 60 mass% or higher and is multilayer, including at least three layers. With the layer arranged on one surface represented as the front surface layer, the layer arranged on the other surface as the back surface layer and the layer arranged between the front surface layer and the back surface layer as the middle layer, among layers of the base paper, (1) the blend ratio of used paper pulp in the front and back surface layers is 20 mass% or lower; (2) the blend ratio of used paper pulp of the middle layer is 90 mass% or higher; (3) the freeness of the pulp used in the front surface layer is CSF 200-400 ml; (4) the ash content of the front surface layer is 7 mass% or less; (5) the z-axis strength of the white paperboard is 300-470 kN/m; and (6) the density of the white paperboard is 0.77-0.87 g/cm. |
