Toughening epoxy adhesives with core shell rubbers

Product overview
Improvements to properties
How it works

Product overview [back]

Technical data (no Specification)

Improvements to properties [back]

• Room temperature curing epoxy adhesives; especially very fast curing systems
• Heat curing epoxy adhesives
• UV radiation curing adhesives

With Albidur®, based on a core-shell silicone rubber, toughened adhesives with a low viscosity can be formulated. No loss in modulus or glass transition temperature is found when using Albidur®, because it is a reactive silicone rubber particle dispersion.

Due to the favorable electrical properties of the silicone rubber used to manufacture the core-shell particles, Albidur® is especially suitable for the formulation of adhesives for electrical and electronic applications.

Albidur® products are applicable for UV curable adhesives because they do not affect the cationic curing mechanism.

How it works [back]

Using Albidur® in adhesive formulations, the same toughening mechanism as with the copolymers of the Albipox® range is used (please refer to chapter 1); however, they are based on a core-shell rubber (Figure 7).  

Figure 7:  Schematic representation of an Albidur® particle

These particles of a defined size (0.1 – 3 µm) are finely distributed and able to chemically link into the epoxy matrix. If a mechanical load is applied to the cured resin, it can be dissipated uniformly in all directions when interfering with a rubber domain.

If a tear has already occurred, it is prevented from propagating, because the elastomer particles stretch perpendicular to the direction of tear and are not torn out, as they are chemically bound into the matrix. Figure 8 shows the finely distributed silicone elastomer particles in the epoxy matrix. 

Figure 8:  Scanning electron microscope image of an epoxy resin modified with Albidur®