Yokohama Rubber creates new urethane adhesive technology

Tokyo, Japan – The Yokohama Rubber Company has developed a two-component polyurethane adhesive that it claims has high strength and elasticity.

Although designed for automotive applications, it should also be useful for electronic devices exposed to harsh heat cycles, the company claims.

Structural adhesives are increasingly important in the automotive sector because of the growing use of multi-material structures. These often combine steel with lightweight materials such as carbon fibre reinforced plastics. It is difficult to join such diverse materials with conventional welding.

The urethane adhesive can achieve maximum tensile strength of 20–40 MPa. This is comparable to epoxy-based products, said the company.

The curing profile of the urethane adhesive has also been improved. ‘[This helps] overcome slow and/or imperfect curing caused by environmental conditions, such as temperature and humidity, which is considered one of the material’s weak points,’ the company said.

Pot life and initial adhesion are both about 2–5 minutes. Changing the mixing ratio controls its physical properties.

Temperature resistance is also much better than conventional urethane adhesives, the company said. ‘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%,’ it said.

The company will now continue to test this new technology, and aims to use it to commercialise next-generation industrial adhesives.