PURPOSE: To obtain a sheet for a waterproof purpose, which is applicable easily and surely to the building part of which the shape is complicated and which needs waterproof work, by a method wherein the adhesive strength of a self-adhesive layer is made in a state satisfying specified conditions.
CONSTITUTION: A sheet for a waterproof purpose is formed by laminating a self-adhesive layer, a modified asphalt layer, and a granulate mineral layer. In this sheet, adhesive strength between the self-adhesive layer and the modified asphalt layer, and between the self-adhesive layer and an object being constructed is made strong enough to restrict at least elastic restoration owing to the residual strain of the modified asphalt. Furthermore, a reinforcing material layer having the rate of extension equal to or higher than the modified asphalt and having a modules equal to or lower than that is placed between materials formed of the asphalt layer. A property of plastic deformation of the sheet is so formed that the rate of extension is 100% or higher, that the strength at that time is 200g/cm 2 or lower, and that a stress intensity of residual strain after one hour at the time when stress is relaxed in such a state that a rate of the extension, 100%, is applied is 60g/cm 2 or lower.
【目的】 本発明は、形状が複雑で、かつ防水工事を必 要とする建物部分、例えば役物廻りと称される建物部分 に容易にかつ確実に適用できる防水用シートを提供する ことにある。
【構成】 （ａ）自着粘着層、（ｂ）改質アスファルト 層、（ｃ）鉱物粉粒層、の各層を少なくとも積層して構 成されている防水用シートにおいて、自着層と改質アス ファルトとの間および自着層と前記防水用シートの施工 対象物との間の接着力が、少なくとも改質アスファルト の残留歪みによる弾性回復を拘束できるだけのものであ ることを特徴とする防水用シート。