Pressure-sensitive adhesive types and compositions

Pressure-sensitive adhesives are generally divided into rubber and resin according to the composition of the main material, and can be further divided into 5 categories.

(1) Natural Rubber Pressure Sensitive Adhesives Natural rubber pressure sensitive adhesives are the earliest and most used rubber type pressure sensitive adhesives. The main components are natural rubber, tackifying resins, softeners, antioxidants, vulcanizing agents, solvents, etc. ,constitute. Since natural rubber has a high cohesive strength and elasticity, as well as good compatibility, pressure sensitivity, and creep resistance, a pressure-sensitive adhesive having good adhesiveness and wettability can be obtained. Because of the presence of unsaturated double bonds in the macromolecular structure of natural rubber, it has the disadvantage of poor aging resistance.

(2) Synthetic rubber and reclaimed rubber pressure-sensitive adhesives These pressure-sensitive adhesives are styrene butadiene rubber, polyisobutylene, polyisoprene, butyl rubber, butadiene rubber, neoprene, nitrile rubber, etc. Synthetic rubber alone Or used as the main body, together with tackifier resin softener, anti-aging agent, mixed solvent, etc.

(3) Thermoplastic elastomer pressure-sensitive adhesives are mainly thermoplastics represented by SIS (styrene-isoprene-styrene block copolymer) and SBS (styrene-butadiene-styrene block copolymer). The elastomer is the main raw material, together with the hot-melt pressure-sensitive adhesive made of tackifying resin, softener, antioxidant, etc., which saves energy and eliminates pollution and is worth promoting.

(4) Acrylic pressure-sensitive adhesives Acrylic acid pressure-sensitive adhesives are acrylate copolymers obtained by copolymerization of various monomers. Generally, it is not necessary to add tackifier resins, softeners, antioxidants and other compounding agents. The pressure-sensitive adhesive properties, with excellent resistance to aging, have evolved very rapidly and are gradually replacing natural rubber pressure-sensitive adhesives.

(5) Silicone and other resin pressure-sensitive adhesives Silicone pressure-sensitive adhesives composed of two organic resins with different molecular weights and silicone rubber, have excellent adhesion to high-energy surfaces and low-energy surfaces. Good high temperature (5000C) and aging resistance. However, the price is higher, the use of amines to limit, other resins such as polyurethane, polyester, ethylene-vinyl acetate copolymer (EVA), PVC, etc. can also be formulated into a variety of pressure-sensitive adhesives.

According to the morphology of pressure-sensitive adhesives, they can be divided into six categories: solvent-based, emulsion-based, hot-melt, reactive, calendered, and aqueous solutions.