Why is it necessary to prepare water-based pressure-sensitive adhesive with high peel strength?

Pressure-sensitive adhesive (PSA, referred to as pressure-sensitive adhesive), is a pressure-sensitive adhesive, only the use of finger pressure, can be closely bonded with the adhesive. With the increasingly strict control of VOC emission, more and more solvent-based pressure-sensitive adhesives need to be changed to water-based pressure-sensitive adhesives or hot-melt pressure-sensitive adhesives. In the existing water-based pressure-sensitive adhesives, there are problems such as temperature resistance and insufficient cohesion, and it is very difficult to achieve the performance of high peel strength.

RAFT is short for Reversible Addition Fragmentation Chain Transfer Polymerization. In addition, RAFT is a type of active/controllable free radical polymerization (CRP). Acrylic ester block copolymer prepared by RAFT emulsion polymerization has high breaking strength, high elongation at break, and high low-temperature balance performance. The pressure-sensitive adhesive prepared by acrylic ester block copolymer has excellent advantages such as high cohesion strength and high-temperature resistance, which solves the shortcomings of conventional acrylic ester emulsion pressure-sensitive adhesive which lacks cohesion and is not resistant to high temperatures at 120℃ or above.

Pressure-sensitive adhesive with high peeling strength is needed in the bonding of automobiles, electronics, TV screens, screen printing, etc. For example, the peeling strength of single-side PET pressure-sensitive adhesive tape prepared into 50um adhesive layer thickness needs to reach more than 15N/25mm. In the preparation process of traditional pressure-sensitive adhesive, viscosifying resin can be added to improve the initial viscosity and peeling strength of the product.

In the acrylic block copolymer emulsion pressure-sensitive adhesive by the physical blending of water-based rosin ester tackifier resin, it was found that the initial adhesion and peeling strength of the adhesive can also be improved, but the improvement effect is not obvious, possibly because the compatibility between acrylate front copolymer and tackifier resin is not good.

Therefore, for the preparation of water-based pressure-sensitive adhesive by acrylate front-end copolymer, it is still necessary to continue to try and explore, preparing products with higher peeling strength and longer adhesion.