LOCTITE® SF 770 is a solvent-based primer designed to improve the adhesion of LOCTITE® cyanoacrylate (instant) adhesives to difficult-to-bond, low-surface-energy materials. It is particularly suitable for polyethylene (PE), polypropylene (PP), PTFE and thermoplastic rubber, where conventional cyanoacrylate adhesives may have difficulty achieving reliable adhesion.
Key Features
Primer for cyanoacrylate/instant adhesives
Improves adhesion to low-energy and difficult-to-bond plastics
Particularly suitable for PP, PE, PTFE and thermoplastic rubber
Very low viscosity, allowing easy application
Transparent to slightly hazy liquid
Fluoresces under UV light, helping inspection and quality control
Solvent-based formulation using isopropyl acetate
Does not itself cure like an adhesive; it prepares the surface for subsequent bonding.
How LOCTITE SF 770 Works
Low-surface-energy plastics such as polypropylene and polyethylene can be challenging for instant adhesives to bond effectively. SF 770 modifies/prepares the surface so that a compatible LOCTITE cyanoacrylate adhesive can develop substantially improved adhesion. Henkel specifically describes it as a primer for making polyolefin and other low-energy surfaces suitable for bonding with LOCTITE instant adhesives.
Typical Applications
LOCTITE SF 770 can be used for bonding applications involving:
Polypropylene (PP)
Polyethylene (PE/HDPE)
PTFE
Thermoplastic rubber
Other difficult-to-bond, low-energy substrates
It is commonly paired with suitable LOCTITE instant adhesives where improved adhesion to these substrates is required.
Application Method
Clean and degrease the surfaces to be bonded.
Apply LOCTITE SF 770 sparingly to the difficult-to-bond surface by brushing, spraying or dipping.
Allow the primer to dry completely before applying the cyanoacrylate adhesive.
Apply the appropriate LOCTITE instant adhesive and assemble the components.
Avoid excessive primer, as Henkel recommends a thin application. �