LOCTITE® SF 770 is a primer used to make polyolefin and other low-energy surfaces suitable for bonding with LOCTITE® instant adhesives. It is only recommended for difficult-to-bond substrates which include polyethylene, polypropylene, polytetrafluoroethylene (PTFE) and thermoplastic rubber materials. LOCTITE SF 770 is not recommended in assemblies where high peel strength is required.