Patent attributes
To provide a pressure-sensitive adhesive sheet according to which air entrapment and blistering can be prevented or eliminated via through-holes, and yet the appearance compares favorably with that of a pressure-sensitive adhesive sheet having no through-holes therein, as a substrate 11 there is used one having a surface roughness (Ra) of not less than 0.03 μm, a lightness (L*) in the L*a*b* color system of not more than 60 in the case of having a chroma (C*) of not more than 60 and a lightness (L*) of not more than 85 in the case of having a chroma (C*) greater than 60, and a contrast ratio of not less than 90%, through-holes 2 passing through the substrate 11 and a pressure-sensitive adhesive layer 12 are made to have a diameter in the substrate 11 and the pressure-sensitive adhesive layer 12 of from 0.1 to 200 μm, a diameter at a surface of the substrate 11 of from 0.1 to 42 μm, and a hole density of from 30 to 50,000 per 100 cm2, in the case that melted portions formed by a laser are present around the through-holes 2 at the surface of the substrate 11, the melted portions are made to have an outside diameter of not more than 50 μm, and in the case that thermally deformed portions are present around the through-holes 2 at the surface of the substrate 11, the thermally deformed portions are made to have an outside diameter of not more than 180 μm.
