Pressure sensitive adhesive coating products and medical bonding materials

In a wide range of applications, general pressure-sensitive adhesive coating products are associated with increased odor problems associated with residual monomers in solvent-based acrylic pressure-sensitive adhesives. Therefore, there is a need to provide pressure-sensitive adhesive coating products that release less odor and reduce residual acrylic monomers. In addition, there is an urgent need to reduce residual C.

Various methods have been tried to reduce the above odor in the preparation of solvent-based acrylic pressure-sensitive adhesives. Examples include attempts to increase the conversion rate by increasing the amount of catalyst, attempts to extend the polymerization reaction time, attempts to add more initiators to the later stages of the polymerization reaction, And a method for adding initiators repeatedly during polymerization reactions

However, although these methods are effective in reducing monomer content, they either add more initiators later in the polymerization reaction or repeat initiators during the polymerization reaction, which sometimes results in significant changes in the properties of pressure-sensitive adhesives over time, especially in the properties of pressure-sensitive adhesives. It is observed that holding power sometimes varies greatly over time

In the Japanese Patent Publication No. Sho 63-175086, it was revealed that the method of adding a monomer scavenger after the polymerization reaction was basically completed to reduce the residual monomer. However, the response of the monomer scavenger is actually inadequate and as a residue is left and therefore cannot reduce the odor to a satisfactory degree. Although odor reduction has been studied, for medical adhesive materials using solvent-based acrylic pressure-sensitive adhesives, more consideration is given to preventing the resulting irritation, rash, cancerous itching, and erythematous lesions in the human body. There is a high requirement to minimize the concentration of residual monomers, so it is desirable to provide a medical pressure-sensitive adhesive in which the residual monomer content does not exceed 0.2 percent (by weight) of the total weight of the adhesive (based on solid content) before the introduction of the drug (Japanese Patent Disclosure No. Hei 5-131022).

For pressure-sensitive adhesive coating products and medical adhesive materials, it is urgent that the pressure-sensitive adhesive changes little over time, especially for medical adhesive materials applied to the human body, during the use of pressure-sensitive adhesive changes over time will have a serious impact on human comfort. For example, pressure-sensitive adhesion increases over time and can damage human skin when the medical adhesive material is removed. In addition, if the hardness of the pressure-sensitive adhesive layer increases over time, the stress placed on the human skin during application will increase the degree of irritation to the human skin.