The Yokohama Rubber Company has established a basic technology for a two-component urethane adhesive with high strength and excellent elasticity. This technology will be applied to the development of adhesives for automobile body structures, an area expected to see rapid growth worldwide. It can be also applied to various industrial adhesives, including those used in electronic devices exposed to harsh heat cycles. The research is based on the company’s renowned urethane adhesive technology for building and automobile window frames.

Multi-material structures combining lightweight materials such as aluminium and carbon fibre reinforced plastic (CFRP) with steel are rapidly coming into use, especially in Europe. This trend is increasing the need for structural adhesives because bonding the various materials used in these multi-material structures is difficult to do with traditional welding. Although the epoxy-based adhesives used to date have high strength levels, their low flexible elasticity to follow movement makes their use with multiple materials difficult. Yokohama Rubber has been conducting research on adhesives that possess the high strength and excellent elasticity required for automobile structures.

In the new technology, Yokohama Rubber succeeded in achieving a maximum tensile strength of 20 to 40Mpa, comparable to that of epoxy- based adhesives with excellent elasticity unique to urethane adhesives with a maximum elongation of 200 to 500 percent. The new technology realizes short takt times that enable both pot life and initial adhesion to be around 2 to 5 minutes. The new technology also greatly improves temperature resistance, maintaining stable physical properties in a much wider range from -30°C to 180°C compared with conventional urethane adhesives. In addition to its excellent dynamic durability, this urethane adhesive demonstrates stable strength and elongation characteristics when the deviation in the mixing ratio of the two components is kept within ±20 percent.

Yokohama Rubber launched its Grand Design 2020 (GD2020) three-year medium-term management plan in 2018. The company will continue to test this new technology and aims to use it to commercialize next-generation industrial adhesives.