Self-Emulsifying Polypropylene Resin Adhesion

The patent removes the emulsifier from the adhesive layer by using a self-emulsification type emulsion where the polymer itself serves as the emulsifier. The polymer contains hydrophilic polar groups that enable water dispersion without requiring external emulsifiers, thus eliminating the harmful residue that would otherwise remain in the adhesive layer and compromise adhesion quality.

The polymer is designed to perform dual functions: as the adhesive material and as its own emulsifier. The hydrophilic polar groups within the polymer chain enable self-emulsification, allowing the polymer to disperse in water without needing separate emulsifier additives. This self-service approach eliminates the need for external emulsifiers that would contaminate the adhesive layer.

The patent employs a simple, cost-effective adhesive composition based on aqueous dispersion of polymer with hydrophilic polar groups. This approach replaces expensive corona discharge or plasma treatment equipment with a straightforward chemical formulation that achieves adhesion through the polymer's inherent properties, eliminating the need for complex surface treatment machinery.

The patent modifies the chemical parameters of the adhesive by incorporating polymers with specific hydrophilic polar groups (such as carboxyl, hydroxyl, or amine groups) that enable direct adhesion to olefin-based resins. This chemical parameter change allows adhesion without physical surface treatment, avoiding expensive equipment while maintaining effective bonding.