| 摘要 |
<p>A shrinkable polyamide film useful for wrapping hams, sausages, etc. The shrinkable film has a hydrothermal shrinking ratio of at least 30% in both MD and TD and a hydrothermal shrinkage stress of from 300 to 700 g/mm2. The film is produced by a process which comprises biaxially stretching a substantially amorphous film composed of a copolymer of 6,6-nylon/6-nylon in a weight ratio of from 5/95 to 25/75 at a temperature of not higher than 120 DEG C. and at a stretching ratio of at least 2.5 times in both MD and TD, and subjecting the stretched film to stress relaxation at a temperature of from the stretching temperature to 170 DEG C., followed by winding it up. Further, a shrinkable film having an oxygen gas permeability of not more than 20 cc/m2x24 hrs. atm. as well as the above properties may be obtained by coating a polyvinylidene chloride resin prior to the stretching so that its solid content after the stretching becomes to be at least 0.5 g/m2.</p> |
