Improve Polymer Performance for Epoxy Resins
US Patent 9,868,751 shows that when using a variety of curing catalysts containing tetraphenyl phosphonium salts of anilide anions (salicylanilide derivative for example) for polymerizing epoxy resins with curing agents (phenolics such as novolacs) at 95 deg C, for encapsulating semiconductor devices, much better performance is obtained than when using non-phosphonium curing agents such as triphenyl phosphine.
The better performance includes higher flowability, higher stability, lower shrinkage and higher curing rates at lower temperatures, achieved in shorter curing times.
Although not addressed in the patent, the higher performance may be related to the combination of having an anionic curing agent paired with a thermally stable quaternary phosphonium cation.
Kim, M.; Kwon, K.; Lee, D.; Chung, J.; Cheon, J.; Choi, J.; (Samsung SDI CO., LTD.) US Patent 9,868,751, 16-Jan-2018
Improve Polymer Performance for Nitrile Rubber
US Patent 9,868,806 describes technology for producing nitrile rubber that is vulcanized without using sulfur. The rubber is a butadiene (58.5 parts)-acrylonitrile (35.5 parts) polymer containing glycidyl methacrylate (6 parts) for crosslinking. When using tetrabutylammonium bromide (4 parts), without the addition of heavy metal compounds, it is possible to achieve a high elongation at break and tensile strength.
Although not addressed in the patent, it is possible that the mechanism is ring opening of the epoxide by the bromide of TBAB followed by continued reaction of the resulting epoxide (addition reaction to an unsaturated bond).
Brandau, S.; Klimpel, M.; Magg, H.; Welle, A.; (Arlanxeo Deutschland GmbH) US Patent 9,868,806, 16-Jan-2018
Contact Marc Halpern of PTC Organics to integrate your expertise and commercial goals with PTC Organics’ highly specialized expertise in industrial phase-transfer catalysis to achieve higher process performance.
