| 摘要 |
<p>1397653 Laminated films LA CELLOPHANE 15 Feb 1973 [16 Feb 1972] 7586/73 Headings B5B and B5N [Also in Division B2] A mono- or bi-axially drawn laminated polyester film consists of (a) at least one layer made from a melt containing few or no crystallization nuclei and (b) at least one layer containing a relatively large number of insoluble catalyst residue particles, so that layer (a) is relatively transparent and non-slippery compared with layer (b) which is relatively opaque and slippery. Layer (a) is preferably thicker than layer (b), so that the film is transparent but is slippery enough to be wound and processed on conventional machinery. The catalyst for layer (a) may be Mu/Sb or Zn/Sb and for layer (b) Ca/Sb or Li/Sb. The polyester may be polyethylene terephthalate. The film may be formed by coextrusion, coating or doubling. The film thickness may be 2 microns or less.</p> |
