Breaking the "Oil Bleed": Novel Reactive Silicone Oil Patent Solves Long-Standing Encapsulant Issue


      A new patent reveals a method to synthesize Reactive Silicone Oil derived from hydroxyl-terminated precursors. This innovation prevents "oil bleeding" in electronic potting compounds, a critical advancement for LED and EV module reliability.
      The National Intellectual Property Administration has granted a patent for "A Reactive Silicone Oil and its Preparation Method and Application" (Application No.: CN202510007096.2).
      Traditionally, manufacturers add inert Dimethyl Silicone Oil to potting compounds to reduce viscosity and improve flowability. However, because this oil does not integrate into the polymer network, it tends to migrate to the surface over time or under high heat. This "oil bleed" causes optical contamination (yellowing of LED lenses) and adhesion failure.
      The newly patented technology solves this problem through molecular engineering. Using Hydroxy Silicone Oil as the starting material, the process involves three steps:
1. Partial end-capping of the hydroxyl groups.
2. Introduction of reactive Si-H (hydrogen siloxane) groups into the backbone.
3. A hydrosilylation reaction with vinyl-terminated silicone oil.
      The result is a reactive diluent that chemically bonds into the cross-linked network of the potting gel. It provides the necessary viscosity reduction during processing but becomes an integral, non-migratory part of the cured material. Tests confirm that compounds formulated with this technology show zero surface migration under thermal aging, marking a significant leap in reliability for high-power electronics.