| 摘要 |
A film that is both biodegradable and flushable, and yet can still act as a barrier to water or other fluids during use, is provided. More particularly, the film contains a water-dispersible core layer that helps the film to lose its integrity after being flushed, as well as a water-barrier skin layer that helps maintain the integrity of the film during use. The nature and relative concentration of the components in the water-barrier layer are selectively controlled to achieve a combination of different functions. That is, the majority of the polymers employed in the water-barrier layer are biodegradable polymers that can be degraded by microorganisms while in an aqueous environment (e.g., septic tank, water treatment facility, etc.). To even further enhance the overall renewability of the layer, a relatively high amount of the biodegradable polymers are starch polymers, which are also renewable. The starch polymers can also minimize the degree of stickiness in the film, which can sometimes result from certain types of synthetic polymers. Even at a high starch content, the present inventors have discovered that films may still be readily formed by using synthetic biodegradable polyesters in combination with the starch to facilitate melt processing.
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