Acrylic/epoxy binders have been used in applications where compositions are required to demonstrate rapid curing and flexible bonding qualities

Acrylic/epoxy binders have been used in applications where compositions are required to demonstrate rapid curing and flexible bonding qualities.

Although acrylic based adhesives generally have good adhesion to different substrates such as plastics, they are generally not ideal for heat resistance. Curable epoxy resins have also been used as adhesive compositions. Epoxy resins form dense polymer networks that generally exhibit desirable thermal properties. But epoxies tend not to bond well to plastics and tend to be brittle, displaying poor impact resistance. Generally speaking, the slow curing of epoxides makes them unsuitable for many industrial applications.

Many adhesives show poor physical properties such as decreased impact strength, poor bonding ability, and curing time for different applications. These physical properties can be improved by adding impact modifiers and other copolymers to adhesives. Unfortunately, although impact modifiers usually improve some physical properties, they usually show high heat resistance. As more and more plastics are used in some industrial applications such as motor vehicle assembly, there is an ongoing need for adhesives that can be used in plastics and metals to form adhesive bonds that remain cohesive under a wide range of adverse conditions. A requirement for a novel fast setting, room temperature curable adhesive, the adhesive assembly has the characteristics of room temperature curing and rapid setting of an acrylic based adhesive, and the heat resistance of an epoxy resin based adhesive. Furthermore, the adhesives required are heat and impact resistant and can be used to bind difficult substrates.

One implementation is a heat-resistant and impact-resistant adhesive. The adhesive includes at least one acrylic-based monomer, at least one epoxy monomer/resin, at least one bifunctional monomer chemically reactive with the acrylic-based monomer and the epoxy monomer/resin, at least one impact modifier, and a catalyst system. The adhesive also contains at least one elastomer.

Another embodiment is a method for manufacturing the adhesive. The method includes steps for bringing a mixture in contact with an activator wherein the mixture includes at least one acrylic-based monomer, at least one epoxy monomer/resin, at least one bifunctional monomer reactive with an acrylic-based monomer and an epoxy monomer/resin, at least one impact modifier and a catalyst system.