| 摘要 |
<p>Controlled permeability films are provided wherein spherical and/or nonporous filler particles having a size greater than the intrinsic thickness of the film are incorporated in a film forming polymer and the film is treated to reduce the carbon dioxide to oxygen permeability ratio of the film. The film can be a multilayer film of polyolefin polymers or copolymers and polyesters. A further embodiment provides a packaging film comprising an outer layer of a styrene-butadiene copolymer to impart clarity, stiffness, crinkle feeling and glossy finish; an internal layer of a barrier film containing inert preferably spherical filler particles larger than the packaging film thickness; and an inner layer of an ethylene alpha-olefin manufactured by the single-site catalyst technology. The nonporous particles are transparent glass so that the multi-layer film has good clarity. The barrier film is an ethylene-vinyl alcohol copolymer and the loading of filler particles is about 0.1%.</p> |
