| 摘要 |
PURPOSE: To inexpensively produce a product excellent in adhesiveness and also excellent in physical stength, elasticity and flexibility by providing a carrier layer having bituminous films applied to both surfaces thereof and providing a large number of holes to the carrier layer. CONSTITUTION: A carrier layer having bituminous films applied to both surfaces thereof is provided. This bituminous film comprises unmodified, oxidized or blown bitumen. For example, a modifying component is a mixture of all of stereoisomers of atactic polypropylene or polypropylene. The carrier layer comprises a thermoplastic film of polyester or polyethylene terephthalate and has a large number of holes. The thickness of this carrier film is 1-500μm, especially pref., 20-80μm. The drilled holes of the carrier film are 0.1-20 mm, pref., 1-5 mm and formed by a punching method, needle drilling or flame drilling. |
