Pressure sensitive adhesives (PSA) have been known about for decades

A pressure-sensitive adhesive is one that [0002] allows a durable connection to the substrate even at relatively weak external pressures and that can be re-separated from the substrate with little residue after use. Pressure-sensitive adhesives are permanently pressure-sensitive adhesives at room temperature, in other words having a low viscosity (viscosity) and high viscosity (tack) enough to mean that they can wet even the surface of the corresponding substrate at low external pressure. Adhesives derive their ability to bond from their adhesive properties, and their ability to reseparate from their cohesive properties. Different compounds are considered the basis of the pressure-sensitive adhesive. The main categories include natural rubber, synthetic rubber, and acrylates).

Pressure-sensitive adhesives based on natural rubber have been known for a long time. The natural rubber has very good cohesive properties. However, poor aging resistance and weather stability are a problem. CA 698 518 describes the operation of preparing compositions by adding high plasticizer content and/or simultaneously strongly plasticizing rubber. Although extremely viscous PSA can be obtained by this method, the relatively high plasticizer content or the severe degradation of the molecular structure of the elastomer to a mean molecular weight of M1 million means that there are limits to the achievability of user-compatible shear strength, even with relatively high subsequent crosslinking.

The use of polymer blends (in which not only non-thermoplastic natural rubber is used, but also segment copolymers with ratios of about 1:1) is essentially an unsatisfactory compromise solution that neither achieves high shear strength (when the self-adhesive tape is used at higher temperatures) nor significantly improves the properties described in this application. JP 07 324 182 A2 describes a multi-stage method in which double-sided tape has a pressure-sensitive adhesive layer based on an acrylic resin-like adhesive, and a second layer containing a blend of isoprene-styrene elastomers, natural rubber, and a non-reactive hydrocarbon resin (Arkon P 100). This tape serves as carpet-laying tape. It also has no demanding shear strength at high temperatures.