The difference between self-adhesive and primer

Self-adhesives and primers differ significantly in definition, working principle, application scenarios, and usage methods. The following is a detailed comparison of the two:

Definition and Composition

Self-adhesive: Generally refers to selectively self-adhesive liquid silicone rubber, a type of silicone rubber that can bond to different substrates during thermocuring without a primer. It achieves self-adhesion through special formulation design, such as introducing tackifiers or modifying the structure of organosiloxanes.

Primer: An adhesion promoter used to improve the interfacial polarity or wettability of the substrate surface. It is typically composed of adhesive monomers, volatile solvents, and water, used to solve problems such as paint peeling and delamination that occur during the surface treatment of plastics or metals.

Mechanism of Action

Self-adhesive: Relying on its special formulation design, it forms chemical bonds or intermolecular forces with the substrate during vulcanization, thereby achieving adhesion. It does not require an additional primer to enhance adhesion.

Primer: By wetting the substrate surface, adjusting the surface free energy of the substrate, and acting as an intermediate layer, it improves the physical properties of the substrate and enhances the adhesive strength. It mainly acts between the substrate and the adhesive, strengthening the adhesion between them.

Product Differences

Self-adhesive: Kanglibang's independently developed and produced PC self-adhesive liquid silicone rubber requires no primer, improves efficiency, reduces costs, increases yield, and features excellent release properties, anti-yellowing, and fewer burrs! Compared to using a primer, it can greatly improve production efficiency and reduce labor costs. It is an A/B two-component addition-curing semi-transparent liquid self-adhesive silicone rubber.

Primer: Primarily used to solve adhesion problems between difficult-to-bond substrates (such as nylon, PP, and metal substrates) and adhesives. Primers play an important role in automotive interior parts, toys, and construction, improving the adhesion between paint and substrate or the bonding strength between adhesive and substrate.

Application Method
Self-adhesive: Relatively simple to use; simply contact the corresponding substrate during vulcanization to form a strong bond. It does not require additional primer treatment or complex application steps.

Primer: The substrate surface needs to be cleaned before use to ensure sufficient contact between the primer and the substrate surface. Then, apply the primer evenly to the substrate surface by spraying or brushing, and wait for it to dry and cure. Finally, apply the adhesive for bonding.