| 摘要 |
<p>A granulated coating compsn. contains a binder opt. with filler, and granules which contain water capable of absorbing heat and vaporising and thereby rendering them porous. This water can be water of crystallisation or of occlusion, pref. of 5-50 wt.% on the hydrated medium. The granules are pref. constituted of hydrated silica, crystalline gypsum, silica gel, or partially dehydrated alumina. Their particle dimensions are pref. 0.1-1.5 mm. The binder is pref. an acrylic or an acrylic-styrene resin. It can be first spread out on the underlying material, and the granules projected onto it, or put on after the granules have been applied to still wet bitumen. Application of the granulated coating to articles made of asphalted cellulosic material, partic. roofing materials, improves their fire-resistance. Slabs of asphalted cellulosic board coated in this way satisfy Swedish, German and French fire tests.</p> |
