SIS-, SBS-, and SEBS- / SEPS- based adhesives have enjoyed strong growth in the pressure sensitive adhesive market, including tape and packaging applications, as well as other markets.

Adhesive formulations based on unsaturated elastomers such as SIS and SBS are more sensitive to oxygen, ozone, light and heat than those based on EVA. Although the use of a nitrogen blanket offers some protection during mixing, additional stabilization is essential to protect the adhesives against oxidative degradation during preparation (high heat and mechanical shear), storage and end use.

Antioxidants, such as Ciba® IRGANOX® 1726 imparts excellent  initial viscosity and viscosity stability to SIS hot melts while reducing color formation.

Because SIS and SBS are sensitive to light, they need to be stabilized in order to protect them from UV induced reactions. For discoloration and retention of adhesive properties, exceptional results can be achieved with both HALS and UVAs. Determining which light stabilizer or stabilizer system to use will vary depending on the adhesive formulation, as there can be distinct differences in the results achieved by either a HALS or UVA.

The appropriate concentration of light stabilizer that is used should be determined by the requirements, keeping in mind that reducing the amount of stabilizer will impact the final results. Synergistic effects can often be achieved by using a combination of a UVA and HALS.

For more detailed recommendations regarding your particular application, please contact us.