| 摘要 |
<p>The invention concerns composite polyester films with good barrier properties relative to gases. More precisely, it concerns a biaxially drawn film, based on polyester and having improved barrier properties relative to gases, characterised in that it comprises a base polyester film of 5 to 50 mum, coated on one of its two surfaces with a deposit containing polyvinyl alcohol and a water dispersible copolyester with sulphonyloxy units, said composite film having permeability to oxygen measured at 23° C. under 50% relative humidity, not more than 5 cm3/m2/24 h. Said composite films have, besides being transparent and having barrier properties, excellent resistance to mechanical stresses, such as in particular crumpling.</p> |
