In the cross-sectional view of sealing gasket, the urethane sealing gasket is composed of urethane-based polymer as a matrix and heat-expandable hollow particles as independent air bubbles. The polyurethane matrix has a crosslinking structure with aliphatic diisocyanate aduct, PTMG, and bi- and trifunctional polyester pre-polymers. Not only by adjusting the mechanical properties with the blowing agent but also by being localized lubricants with talc on the surface, both excellent sealing and opening properties could be realized.
- Toshinori Moriga
- Naoki Aoyama
- Keiji Tanaka
