R Flux / Fluxing agent without...  Go To Index Recrystallization  

    RA Flux / Fluxing agent with activator

    The abbreviation RA stands for rosin activated. A fluxing agent, the activity of which was increased for coniferous resins by adding relatively large amounts of an activator substance. Mostly amines or amine hydrohalides are used for this purpose. In the U.S. Military standard MIL-F-14256, modified colophony or colophony obtained from balsamic resin, wood rosin or tall oil rosin is dissolved in a nonhalogenic solvent and then the activator is added to this solution in order to increase wettability. Properties: acid number AN > 130; solids content > 51 %; solution resistance > 50,000 Ωcm; SIR ( Surface Insulation Resistance) > 500 MΩ (2 hours after returning to normal state, upon heating and humidification at 85 °C and RH=85%); solder extension > 100 mm2 on a brass plate. In this case, the admissible halogen content (overall content of F, Cl and Br) in 1 g of solids 0.284 ml in titration corresponds with 0.1N silver nitrate.