| 摘要 |
<p>Decorative sheet-type covering material having both PVC and polyurethane wear layers is made by first forming a sheet of gelled foamable PVC plastisol or organosol on a substrate. A layer of nonfoamable PVC plastisol or organosol is then applied to the gelled foamable layer and gelled, but not cured. A layer of polyurethane is then applied to the gelled nonfoamable layer and the entire sheet is heated to a temperature sufficient to decompose the blowing agent in the foamable layer and cure both of the PVC layers and the polyurethane layer.</p> |
