MODIFIED ETHYLENE-BASED FILMS TO PROMOTE ISOCYANATE CHEMICAL REACTIONS IN POLYURETHANE LAMINATING ADHESIVES

摘要

In the construction of a multilayer film in which an ethylene-based polymer layer is joined to one another layer by a polyurethane (PU) adhesive, the rate of cure and the degree of cure of the PU adhesive are accelerated by incorporating into the ethylene-based polymer layer a functional compound with active hydrogens, e.g., a polyol, and/or a cure catalyst, e.g., an amine, zinc or tin-based compound. The catalyst and reactive functionality may be present on the same molecule (e.g. alkoxylated amine or zinc ricinoleate). The catalyst and isocyanate reactive compound will migrate into the PU adhesive over time and accelerate the rate and promote the degree of PU adhesive cure, and the functional compound will promote the migration of the cure catalyst into the PU adhesive. In turn, this accelerated cure inhibits the migration of residual, monomeric amines from the PU adhesive into and through the ethylene-based polymer.