MORESCO Releases a Reactive SBC-based Hot Melt Sealant

Japan's MORESCO Corporation has recently announced the release of a reactive SBC-based hot melt sealant that can also be foamed. The new sealant is used for headlamp lens, where it would replace butyl rubber. It also finds use in auto interiors.

According to the company, MORESCO hot melt sealant is very tacky and soft, with good flow properties, making it able to handle applications with complex shapes. When applied, moisture in the air is sufficient to catalyze cross-linking, and no heat needs to be applied. Cross-linking gives the SBC-based sealant its heat resistance of up to 180°C in comparison with just 120°C for a non-reactive type.

Moreover, MORESCO has been proactively developing polyolefin-based hot melt adhesives for use in automobile interiors over the years. Reactive hot melt adhesives contain no solvents and boast improved heat resistance. Because they are solvent-free, major automobile producers have adopted this series of adhesives for its human and eco-friendly features.

Some people like the unique smell of new cars, but what they really smell are the solvents used for adhesives. Many of these solvents contain hazardous chemical substances, which can cause dizziness, headaches, and breathing problems. However, hot melt adhesives don't lead to such symptoms owing to no solvents contained.

The solvent-free MORESCO-Melt RO series is used for adhesion of door trim. It is a reactive hot melt adhesive that cures through the moisture content in the air or the material to be adhered. It shows high adhesive properties and heat resistance for polypropylene (PP) parts.

MORESCO has also developed the heat-resistant MORESCO-Melt RAC-90 for bonding of PP to steel as well as acrylonitrile-butadiene-styrene (ABS) resin. This balanced adhesion towards both ABS and steel allows the use of both PP and ABS in a single component assembly. Adhesive force towards ABS is reportedly 10-times that of conventional adhesives. RAC-90 also features extended open time of up to 45 seconds, resulting in improved workability.

A final new product is TN-877, featuring excellent PP adhesion and retention, as well as a long open time of up to 45 seconds. The material is particularly suitable to adhesion of heel pads and deck boards in automobiles.