Trace analysis of polysiloxane from pressure sensitive adhesive release liners

Abstract

According to the required standard of silicone and amide content in the release liner of pressure sensitive adhesive (PSA) in the hard disk assembly process, there should not be silicone and amide compounds present in the release liner of PSA. In this research, various types of release liners and PSAs from Flex Con, including 90 PFW, 150 Poly STH-9, Specsok-8, EX200 Poly SC-9, ST-2412014, ST-2412024, ST-2412034 and ST-2412044, were used as samples. The amount of polysiloxane compounds were determined by using FTIR analysis technique, the amounts of polysiloxanes were detected at 0.09 ng/cm2, 0.08 ng/cm2, 0.60 ng/cm2, 0.42 ng/cm2, 0.11 ng/cm2, in release liners 90PFW, 150 Poly STH-9, Specsok-8, EX200 Poly SC-9, labels namely ST-2412014, ST-2412024, ST-2412034 and ST-2412044, respectively. The types of polysiloxane compounds were also determined by using localized extraction with methylene chloride, which subsequently injected into GC/MSD. The vapor of polysiloxane compounds that volatilize at 85 ํC within 3 hours in the DHS chamber was collected and later thermally desorbed via ATD (Auto Thermal Desorption instrument) into GC/MSD. Some of the polysiloxane compounds in release liners of PSA were identified as 3-Isopropoxy-1, 1, 1, 7, 7, 7-hexamethyl-3, 5, 5 tris (trimethylsiloxy) tetrasiloxane mixed with 1, 1, 1, 5, 7, 7, 7-heptamethyl-3, 3-bis (trimethylsiloxy) tetrasiloxane and also dodecamethyl cyclohexasiloxane. Moreover, the other harmful organic compounds to the hard disk performance were detected.