Advances in Adhesive Technology for Bonding Liquid Silicone Rubbers to Plastics and Metals

Summary based on original article by Paul A. Wheeler, Tarek A. Agag, Brian P. Carney, Rebecca S. Cowles and Douglas H. Mowrey, LORD Corporation

As the global liquid silicone rubber (LSR) market continues to grow, especially for electronics and medical device manufacturers, so does the need for sophisticated methods to bond LSR to various substrates. A recent study by LORD corporation tested three new adhesive systems for their ability to bond LSR to polycarbonate, thermoplastic elastomer, polyamide and stainless steel—a challenge to overcome due to LSR’s ultra-low surface energy of around 20 mN/m and chemical resistance. The study was designed to improve upon existing silane technology, which proves difficult to apply and usually requires plasma treatment to promote bonding. Three proprietary LORD adhesives were tested: LORD A is an aqueous hybrid whose primary solvent is water, and LORD B and C are solvent-borne. LORD A and C bonded to all LSRs; LORD B bonded to two. The study concludes the three adhesive systems were successful in bonding multiple platinum-cured silicones to multiple substrates that do not require special surface preparation. One system is a water-based, environmentally-friendly option.