Introduce the polar group-containing monomers acrylic acid, amine acrylate, hydroxyethyl acrylate, etc. into the polyacrylic pressure-sensitive adhesive by copolymerization, or blend a more polar tackifying resin with a rubber-type pressure-sensitive adhesive. Both can add the molecular polarity of the pressure-sensitive adhesive. The addition of the polarity of pressure-sensitive adhesive molecules can significantly improve the peel strength of pressure-sensitive adhesive products for polar adhered materials. As shown in Table 1:

 

Table 1 is a set of typical test data. Remarkably, the molecular polarity of acrylic acid and acrylamide is larger than that of methacrylic acid and methacrylamide. They also contribute more to the molecular polarity of the added copolymer. The effect is also significant. So people often introduce the acrylic method to improve the 180 ° peel strength function of polyacrylate pressure-sensitive adhesive. We have previously studied the effects of the amount of acrylic acid in the solvent-based polyacrylate pressure-sensitive adhesive monomer formulations on their 180 ° peel strength and other pressure-sensitive adhesive functions of their pressure-sensitive adhesive products. The test results are shown in Table 2. The data indicate that with the addition of the amount of polar monomer AA, the addition of the polarity of the copolymer molecule, the 180 ° peel strength is significantly increased, and the shear creep persistence of the pressure-sensitive adhesive is also significantly improved, but the initial adhesion function of the pressure-sensitive adhesive There is a regular decline.

 

The polarity of pressure sensitive adhesive molecules not only increases the mutual force between molecules on the bonding interface, improves the interface adhesion conditions, but also adds the interface adhesion work. Then, the mechanical properties and rheological properties of the pressure-sensitive adhesive layer were also changed, for example, cohesive strength and elastic modulus were added, and the peeling problem and bulk viscosity were improved. These all affect the 180 ° peel strength of the pressure-sensitive adhesive and other pressure-sensitive adhesive functions.