SiwoPUD®-U-678

SiwoPUD®-U-678 is an anionic high-molecular-weight waterborne polyurethane dispersion developed as a raw material for heat-activated polyurethane adhesives. It features a relatively high thermal activation temperature, good anti-blocking properties, strong initial tack, and high bonding strength, making it suitable for demanding waterborne adhesive applications.

Compared with U-658 and U-674, U-678 offers improved hydrolysis resistance and aging resistance. It provides excellent adhesion to most synthetic and natural materials and is suitable for heat-activated bonding of fabrics, leather, packaging materials, and other substrates. It also offers good compatibility with other waterborne resins, including slightly acidic resin systems.

For enhanced high-temperature bonding performance, adding 2–5% water-dispersible polyisocyanate curing agent, such as SIWO EC-600, can significantly improve bonding performance at elevated temperatures. For heat-activated bonding, a temperature of 80–90°C or higher is recommended to ensure sufficient activation of the dried adhesive layer. The actual activation temperature depends on applied pressure, dwell time, and the substrates being bonded.

With its combination of high bonding strength, anti-blocking performance, hydrolysis resistance, and aging resistance, SiwoPUD®-U-678 is a suitable choice for manufacturers developing durable heat-activated waterborne polyurethane adhesive systems.