SBS thermoplastic elastomer is a styrene-butadiene-styrene triblock copolymer, it has both the solubility and thermoplastic polystyrene (PS), and the flexibility and resilience of butadiene rubber (PB), both thermoplastic and vulcanized rubber dual characteristics. These properties are due to the thermodynamic incompatibility between the end of PS and the middle part of PB. The terminal aggregation area of PS is glassy at room temperature and ACTS as a rigid network crosslinking point. However, when PS is higher than the viscous flow temperature of PS, PS is viscous and the crosslinking is destroyed, so that it can be plastic processed. Because of these characteristics of SBS, it becomes an important material for preparing pressure-sensitive adhesive.
　　Solvent - based SBS pressure-sensitive adhesive has a lower viscosity, which makes it possible to prepare adhesive with higher solid content and suitable for coating. This saves not only the solvent, but also the energy required to make the solvent evaporate.
　　The choice of the SBS
　　SBS elastomer is the main material of SBS, its structure fractal and star two categories. Linear SBS has low molecular weight, good solubility, low viscosity and low cohesive strength.
　　SBS has higher relative molecular weight, cohesive strength, physical crosslinking density, heat resistance and elastic modulus than linear SBS. But star SBS dosage too much, will increase the adhesive shrinkage stress. The internal stress in the adhesive joint will cause the strength of the joint to drop, making the adhesive in the cured rubber layer of poor flexibility, brittleness. In addition, adhesive and adhesive molecules need to be mutual diffusion into a solid joint. The infiltration of star SBS elastomer is weaker than that of linear SBS elastomer. Therefore, SBS1401 (yh-792) with linear structure was selected as the main material.
　　Common solvents such as: toluene, dichloroethane, carbon tetrachloride, vinyl acetate, cyclohexane is a good solvent SBS; N-hexane, heptane, petroleum ether, solvent gasoline, acetone and so on are bad solvents, a single solvent is difficult to meet the comprehensive requirements, generally using a good solvent and bad solvent composed of binary or multiple mixed solvents. Mixed solvents in the poor solvent evaporation rate must be faster than good solvent. Otherwise, the surface of the film rough, bond strength reduced.