High temperature tolerance epoxies

Epoxy adhesives are generally limited to applications below 121 °C. Some epoxy adhesives tolerated short-term service at 260°C and long-term service at 149-260°C. These systems were formulated especially for thermal environments by incorporation of stable epoxy co-reactants or high-temperature curing agents into the adhesive. One of the most successful epoxy co-reactants is an epoxy-phenolic alloy. The excellent thermal stability of the phenolic resins is coupled with the adhesion properties of epoxies to provide an adhesive capable of 371 C short-term operation and continuous use at 177°C. "... 

Primary and secondary aliphatic amines react relatively rapidly with epoxy groups at room or lower temperature to form three-dimensional crosslinked structures. The resulting cured epoxies have relatively high moisture resistance and good chemical resistance, particularly to solvents. They also have moderate heat resistance with a heat distortion temperature in the range of 70 to 110°C. Thus, short-term exposures of cured adhesive joints at temperatures up to 100°C can generally be tolerated. 

Since absorbed water can cause catalyst decomposition and hence incomplete polymerization and since lactam monomer flakes are highly hygroscopic, the melting of monomer is carried out under appropriately controlled temperature and humidity conditions. All additives are also completely dried and then mixed with the monomer in stainless steel vessels while flushing with inert gas under thermostatically controlled temperature. Molds can be of the single type fabricated from silicone rubber, epoxy, or sheet steel or the more expensive tool steel used in tight tolerance cast-to-size parts casting. 

The ideal die attach material has a short cure time at a relatively low-cure temperature, exhibits low moisture absorption, provides good adhesion to multiple surfaces, contributes low stress to the die and can be processed within a very tight tolerance. Many epoxies are now available meet some of these demands to a high degree, yet each material has limitations. 

The value of epoxy and other resins is in their versatility they are used in a wide variety of products and applications that have become central to modern society. Without epoxy resins and technology, many products would not exist, and modern society would be very different. Epoxy resins cure to a tough, resilient, and very durable solid that has high resistance to impact breakage, fracturing, erosion, and oxidation. They are also reasonably good thermal conductors that tolerate rapid temperature changes very well. 

A white, low odour, low viscosity, low toxicity epoxy laminating resin designed for close dimensional tolerance automotive and aircraft tooling applications, offering high impact resistance. Two hardeners are available, LH-101 offering a standard room temperature cure, and C-201 offering a slow room temperature cure. 

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