摘要 |
<p>Polymer structure comprising a continuous outer microcellular layer and an inner integral polymer core, is characterised by an abrupt change of density at the unction of the outer and inner components. The outer layer has a thickness of >=0.25 mm. The chemical compsn. of both outer and inner layers is uniform and the main bonding is via isocyanurate entities. The inner core contains a reinforcing cloth structure.</p> |