| 摘要 |
<p>The inner layer (2) of a two-layer coating (2,3) to give an aroma- and vapour-barrier on paper or cardboard (1) consists of: (a) amorphous SiO2, Al oxide, PVA and a copolymer of styrene-butadiene with acrylonitrile; or (b) silicic acid (opt. pptd.), PVA and the same copolymer as in (a). In each of (a) and (b) additional components may also be present.</p> |
