| 摘要 |
A degradable but not heat-sealable film substrate is made heat-sealable by coating it, discontinuously, with a nondegradable or degradable thermoplastic formulation. The desired degradability of the substrate is determined by the expected mode of disposal for the product in which the film is to be used. Discontinuity in the coating exposes the degradable substrate, making the substrate susceptible to degradation by microorganisms or by hydrolyzing media. The invention is effected by adhering a discontinuous nondegradable or degradable thermoplastic coating to one or both sides of a biodegradable or hydrolyzable film, to yield a heat-sealable film whose inherent ability to degrade is not compromised and whose rate of degradation is not materially affected. Films in accordance with this invention may be pervious or impervious components of disposable consumer and medical products, and as packaging materials for such products.
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