摘要 |
A polymer film consists essentially of a biaxially-oriented high nitrile addition polymer containing at least 80% acrylonitrile repeating units and an impregnant in the form of a low molecular weight non-volatile polyalkylene glycol ether, preferably trimethylene glycol, dispersed in the polymer in a sufficient amount to plasticize the polymer and increase film toughness. …<??>In producing the film, a continuous strip of a polymeric aquagel having a substantially constant water content is passed through an aqueous bath containing the impregnant so that the impregnant is absorbed into the aquagel. The impregnant is added to the bath at a rate to maintain a substantially constant concentration of impregnant in the bath and allow the concentration of water components in the aquagel and bath to reach equilibrium. |