| 摘要 |
<p>1535654 Pressure-sensitive record sheets GREAT NORTHERN NEKOOSA CORP 28 June 1977 [16 Dec 1976] 27046/77 Heading D2B A pressure-sensitive record sheet is provided with a barrier layer comprising clay and an alkali metal sulfite between the base sheet, which contains ground wood, and an overlying layer comprising microcapsules containing a colour former in order to prevent yellowing.</p> |
