Activated magnesium oxide is one of the important raw materials for chloroprene adhesive. The activity of magnesium oxide directly reflects the strength of the reaction ability between magnesium oxide and chloroprene adhesive. The higher the activity of magnesium oxide, the faster the reaction rate with chloroprene adhesive. Secondly, the role of active magnesium oxide in chloroprene adhesive is multifaceted, mainly playing a role in preventing scorching, acid absorption, vulcanization crosslinking, and resin chelation. Due to the high activity and large specific surface area of activated magnesium oxide, its addition to chloroprene adhesive can improve the adhesive strength and initial adhesion, as well as enhance the transparency of the adhesive. Its biggest feature is that it can prevent delamination and precipitation of the adhesive. Usually, the activity of active magnesium oxide is represented by the magnitude of its iodine absorption value. An iodine absorption value below 40 indicates low activity, an iodine absorption value between 40-100 indicates medium activity, and an iodine absorption value above 100 indicates high activity. Meanwhile, high-quality chloroprene adhesives mostly use highly active magnesium oxide.

The main components of chloroprene adhesive are not only chloroprene rubber, but also resin, and resin has a significant impact on chloroprene adhesive. The function of resin is to prolong the bonding retention time, improve cohesive strength, and enhance adhesive strength. Commonly used resins include terpene phenolic resin, tert butyl phenolic resin, rosin resin, petroleum resin, etc. Among them, tert butyl phenolic resin has the best effect.

If resin is directly added to chloroprene adhesive, not only will the modification effect be poor, but it is also prone to delamination. Only by pre reacting resin and magnesium oxide before adding, can the heat resistance, storage stability, layer stability, and bonding strength be significantly improved. The activity of magnesium oxide, the quality of resin, reaction time, reaction temperature, and the selection of catalyst and solvent can have a significant impact on the pre reaction.

During the chelation reaction, tert butyl phenolic resin reacts with activated magnesium oxide, requiring a high specific surface area, high activity, moderate packing density, good dispersibility, and fine particle size of the activated oxygen nectar. If the packing density is low and the operating environment is harsh; If the packing density is high, precipitation is prone to occur. In addition, it is necessary to avoid moisture absorption by active magnesium oxide. Due to the adsorption of water on the surface of active magnesium oxide, some of the inner and outer surfaces of the magnesium oxide become moist, weakening the activity of the active magnesium oxide and affecting the chelation reaction. Therefore, before using activated magnesium oxide, it is necessary to strictly control the moisture content of magnesium oxide, and it is best to dry it.