Flexible polyureas for flexible packaging adhesive without aromatic amine migration

A multi-layered laminated film comprising a layer of an adhesive applied to one or more substrate layers, the adhesive comprising a reaction product of:

• (A) an aliphatic polyisocyanate having a number average molecular weight of from 132 to 700, wherein, if (A) includes a plurality of aliphatic polyisocyanates, the plurality of aliphatic polyisocyanates has a number average molecular weight of from 132 to 700;
• and
• (B) a polyaspartate comprising a reaction product of:
• (B1) a polyamine having a molecular weight of at least 240, and
• (B2) a Michael addition receptor,
• wherein the polyaspartate has a structure corresponding to formula (I)
• wherein:
• n is an integer of at least 2,
• X is a C3 or C4 polyether having a molecular weight ≥208,
• R1 and R2 each independently represent organic groups that are inert to isocyanate groups under reaction conditions, and
• R3 and R4 each independently represent hydrogen or organic groups that are inert to isocyanate groups under reaction conditions,
• wherein the adhesive develops an acceptable bond strength to a substrate, defined as having a minimum of 150 g/in. measured @ 23° C. according to ASTM D 1876-01 or substrate tear, in less than five days after the substrate is laminated with the adhesive.