A Study on the Electron Beam Crosslinking of Acrylic Pressure Sensitive Adhesives for Polarizer Film

Abstract

New pressure sensitive adhesives (PSAs) for polarizer film were prepared by electron beam (e-beam) radiation to acrylic copolymers, and their adhesive properties were investigated. The acrylic copolymers were synthesized by free radical polymerization of n-butylacrylate (BA), 2-hydroxyethyl methacrylate (HEMA), and acrylic acid (AA). The acrylic copolymers were coated on PET release films to a thickness of 25 µm, laminated to polarizer films, and then radiated with e-beam at room temperature. Gel fractions of all the acrylic copolymers after e-beam radiation at 50 kGy were higher than 93%, and their crosslinking densities were increased with increasing the content of HEMA units. PSA prepared by e-beam radiation of acrylic copolymer synthesized with a feed ratio of BA/ HEMA/AA = 89.5/10/0.5 (w/w/w) at a dose of 50 kGy exhibited the best adhesion performances in terms of peel strength, creep resistance, durability and reliability, and light leakage. It is expected that the preparation method of PSAs via e-beam irradiation will improve the producibility and workability of polarizer film for liquid crystal display.Keywords: pressure sensitive adhesives, polarizer film, acrylic copolymers, electron beam radiation.

Improvement in wettability of pressure‐sensitive adhesive on silicon wafer using crosslinking agent with siloxane groups

“…However, other parts such as linear or branched polymers are soluble in the solvent. Therefore, the extent of crosslinking is usually evaluated by measuring the content of insoluble gel portion 21, 22. The extent of crosslinking in acrylic PSAs was controlled by varying both the contents of crosslinking agent and the functionality of crosslinking agent.…”