Modified natural rubber latex pressure sensitive adhesive

At present, natural rubber pressure-sensitive adhesive is mainly solvent-based. The solvent has some defects such as environmental pollution, inflammability, and inconvenient processing. Because the molecular weight of natural rubber latex is too large and the molecular chain is short of polar functional groups, the initial adhesion and peeling strength of natural rubber latex pressure-sensitive adhesives are not as good as those of corresponding solvent-based pressure-sensitive adhesives.

The modification methods of natural rubber are known only by one-time modification, such as epoxidation, chlorination, hydrogenation, copolymerization, degradation, etc. These methods have certain limitations on the improvement of the properties of natural rubber, and in addition to degradation method, other modification methods have further increased the molecular weight of natural rubber, and the modified natural rubber is suitable for the production of tires or other hard products, not used as adhesives. At present, there is no public report on the modification of natural rubber by copolymerization after degradation and the modified natural rubber latex sensitive adhesive.

The purpose of this paper is to overcome the deficiency of existing technology and provide a modified natural rubber latex pressure-sensitive adhesive and its production method.

It is achieved in this way: first of all, the natural rubber is degraded by the well-known degradation method, and the molecular weight of the latex after degradation is controlled to be 3000~150000. After degradation, copolymerization was carried out by the known method, and the control copolymerization rate was 5~50%. Modified natural rubber latex after condensation and copolymerization is used as the base resin of pressure-sensitive adhesive, and then mixed evenly with known viscosifier resin and known modifier according to known method to obtain pressure-sensitive adhesive. The proportion of each component of pressure sensitive adhesive is: modified natural rubber emulsion 30~60%, viscosifying resin 30~60% modifier 1~15%.

Compared with the prior art, it has good fluidity and lubricity of the surface of the pressure-sensitive adhesive and the adhesive, strong adhesive force, high adhesive strength, stable performance and wide application. Simple production method, less required equipment, low cost, no by-products, no environmental pollution, good economic benefits, and other advantages.