The silicone pressure-sensitive adhesive is added with an appropriate amount of condensation catalyst to connect certain molecules of the rubber and the resin through the mutual condensation reaction of silanol groups. Preventing excessive phase separation of the rubber and resin after mixing can improve the cohesion of the silicone pressure-sensitive adhesive The available condensing agents are organotin compounds and amines or other bases. The amount should be as small as possible. After the reaction, neutralization and a small amount of inhibitor can be added, and some of the condensation catalyst can be thrown away.
Silicone pressure-sensitive adhesive is an important category in pressure-sensitive adhesives and pressure-sensitive adhesives. There are addition molding and condensation type silicone pressure-sensitive adhesives. The former KL-2610 is used for platinum vulcanizing agent to catalyze the coating of liquid silicone rubber on the surface of PET substrate. It is made of silicone colloid, adhesive, curing agent, platinum water and other components; the latter KL-9301 is applied to the silicone rubber coated PI high temperature tape, green tape and other products of peroxide BOP system.
In the silicone pressure-sensitive adhesive, the ratio of the raw rubber and the MQ resin has a great influence on its peeling force and initial tackiness. Among them, the MQ resin is mainly used as a structural reinforcing agent and a tackifier. When the pressure-sensitive adhesive is attached to some adherends with high surface energy and high polarity, polar groups such as hydroxyl groups and carboxyl groups contained on the surface of the adherend can be bonded to the pressure-sensitive adhesive through hydrogen bonding, so that pressure Sensitive adhesives show good adhesion properties to them.
Since the silicone structure in the silicone pressure-sensitive adhesive is hydrophobic, its surface will not adsorb water molecules in the air, and the pressure-sensitive adhesive itself contains very few polar groups (such as hydroxyl groups), so hydrogen The bonding mechanism may be that the pressure-sensitive adhesive layer acts as a hydrogen bond acceptor and the polar sticker layer acts as a hydrogen bond donor.
When the silicone pressure-sensitive adhesive is used to attach silicone rubber products, the above-mentioned hydrogen bonding effect cannot be achieved due to the low surface energy and low polarity of the silicone rubber itself, which makes the conventional silicone pressure-sensitive adhesive suitable for organic Silicone rubber products have insufficient peeling force.
Contact：Sharon Song(Sales manager)
Zhejiang Runhe Organosilicone New Material Co.,Ltd(Factory)
Zhejiang Runhe Chemical New Material Co.,Ltd(Exporter)
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