Industry background on the development of a high molecular weight solvent-based acrylic pressure sensitive adhesive

Acrylic pressure sensitive adhesive has been widely used in product packaging, printing, medical and health industries, among which solvent acrylate pressure sensitive adhesive because of its good adhesion and pressure sensitive, excellent corrosion resistance and aging resistance, set many advantages in one and in the acrylic pressure sensitive adhesive industry occupies an important position.

However, currently commonly used solvent-based acrylic pressure sensitive adhesive has the problem of initial viscosity and holding viscosity can not be both, high initial viscosity of acrylic pressure sensitive adhesive its holding viscosity is poor, and high holding viscosity of acrylic pressure sensitive adhesive its initial viscosity is weak, thus limiting the use of acrylic pressure sensitive adhesive range and service life.

Moreover, the molecular weight of the solvent – based acrylate pressure sensitive adhesive synthesized at present is low. Molecular weight is one of the main factors affecting the properties of acrylic pressure sensitive adhesive. However, the increase of molecular weight will make the viscosity of polymer solution rise, especially in the polymerization process, the increase of viscosity will cause the heat of polymerization reaction is not easy to lose, resulting in detonation.

Therefore, generally through free radical polymerization in solution synthesis of acrylate molecular weight are relatively small, which is related to the polymerization solvent, polymerization process, etc. The chain transfer coefficients of the monomers synthesized acrylate pressure sensitive adhesive were different in different solvents, which led to the significant effects of solvents on the polymerization reaction rate, chain termination rate, polymer viscosity, molecular weight and distribution.

In addition, it is difficult to control the reaction process of solvent-based acrylate pressure sensitive adhesive in the synthesis process, which will result in its low conversion rate and poor performance. As a result, polymerization process also becomes an important factor affecting the pressure sensitive property of acrylate. Therefore, a solvent – based acrylic pressure sensitive adhesive with initial adhesion, stripping and retention is needed.