Starting around 200,000 years ago with birch-bark tar, adhesives have played an important role in the advancement of the human species.1 The constant material innovations occurring in today’s modern society create a variety of bonding challenges for engineers, scientists and builders. Aliphatic diisocyanates (ADIs) are one solution to these challenges and play a pivotal role in the construction of buildings, vehicles and other products that improve lives.
Polyurethane adhesives use ADIs in a variety of markets as a raw material to create high-strength bonds that resist color change when exposed to ultra-violet (UV) rays. These ADI-based adhesives offer a flexible and advanced bond to a wide range of substrates, which is why more than 75 percent of their applications are in the construction, packaging and transportation markets.
Aliphatic Diisocyanates Create Valued Products
ADI-based adhesives see a large portion of their use in the construction, packaging and transportation markets, but this versatile material can be found in other notable industry applications as well. For instance, ADI adhesives are used in the marine industry to provide structural support for marine vessels, offshore oil platforms, underwater equipment and recreational watercraft. They also play a critical role in the footwear and textile industries, helping to adhere soles to the bottom of shoes and to attach the bonding layers of performance textiles. In addition, polyurethane adhesives based on ADI are used in industrial applications, machinery, furniture and other market segments.
ADI-based adhesives provide several key benefits, including:
- Excellent weather resistance, especially resistance to color shift from UV exposure;
- Enhanced flexibility, allowing for dynamic use conditions;
- Superior adhesion to a wide range of substrates, including plastics; and
- Strong performance in low-temperature environments
Polyurethane adhesives based on ADIs can be formulated with either one or two components depending on the desired properties. One-component adhesives are moisture curing, and two-component adhesives cure at room temperature. Due to the room temperature cure of two-component systems, the components cannot be combined until the moment of application. As always, personal protective equipment (PPE) should be worn during all applications in order to protect the professional applicator from potential hazards involved with handling reactive materials.
Meeting Market Needs
With such a diverse field of application, ADI chemistry is well positioned to help meet the needs of developing markets. A large source of increasing and changing needs is the automotive industry, which is progressively changing the materials used to build vehicles in order to increase fuel efficiency. ADI-based adhesives are able to assist automotive manufacturers by helping to bond automotive substrates and reduce vehicle weight.
In automotive and other industries, process efficiencies are being enhanced by reducing the temperature required to cure adhesives. In turn, this helps manufacturers lower their energy consumption. In coordination with industry environmental efforts and stricter environmental standards, ADI-based polyurethane adhesives are being developed with lower volatile organic compound (VOC) emissions by using waterborne and high-solid formulations.2
Strong Benefit to the U.S. Economy
In the United States, the 2019 overall polyurethane industry supported nearly 260,000 jobs and $89.3 billion in output.3 Polyurethane adhesives have a significant market presence with nearly 320 million pounds produced in 2014 in the United States. Construction is the largest market with 114 million pounds of material produced in 2014. Packaging and transportation were the next highest with 95 and 41 million pounds produced respectively.2
Polyurethane adhesives based on ADIs provide an important value both economically and technologically. By using ADI-based adhesives, the world is able to enjoy fuel-efficient vehicles, elegantly designed skyscrapers, functional and stylish footwear, and many other beneficial products.
1 Mazza, P; Martini, F; Sala, B; Magi, M; Colombini, M; Giachi, G; Landucci, F; Lemorini, C; Modugno, F; Ribechini, E (January 2006). "A new Palaeolithic discovery: tar-hafted stone tools in a European Mid-Pleistocene bone-bearing bed". Journal of Archaeological Science. 33 (9): 1310. doi:10.1016/j.jas.2006.01.006.
2 2018 End-Use Market Survey on the Polyurethanes Industry, Center for the Polyurethanes Industry, American Chemistry Council.
3 Center for the Polyurethanes Industry 2019 Economic Benefits Study