Polyurethane type UV viscosity-reducing adhesive based on dimer acid and preparation method of polyurethane type UV viscosity-reducing adhesive

The invention provides a dimer acid-based polyurethane UV viscosity-reducing adhesive and a preparation method thereof, and relates to a new material technology, in particular to a UV viscosity-reducing adhesive technology in wafer manufacturing. The polyurethane type UV viscosity-reducing adhesive comprises a hydroxyl-terminated dimer acid-glycidyl methacrylate tripolymer prepolymer, diisocyanate and a photoinitiator. A hydroxyl-terminated dimer acid-glycidyl methacrylate tripolymer prepolymer is introduced into the UV viscosity-reducing adhesive, dimer acid belongs to a bio-based material and is wide in source, two carboxyl groups and a double bond exist in molecules of dimer acid, the molecular weight is large, the 180-degree peel strength of the UV viscosity-reducing adhesive before UV irradiation can be improved and can reach 20.4-34.7 N/25 mm, the strength is reduced to 0.7-2.7 N/25 mm after UV irradiation, and the adhesive strength can reach 20.4-34.7 N/25 mm after UV irradiation. And the viscosity red