Applications of epoxy resins and their latest developments

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Epoxy resins become useful only after being hardened with a curing agent, and one of its features is the diversity of mixing processes. By selecting different curing agents, modifiers, toughening agents, and fillers or pigments, epoxy resins can be endowed with various desired properties, thereby **expanding their range of applications and making them highly versatile. There are many factors that affect the use of epoxy resins; the key ones include: formulation design (such as the choice of resin, curing agent, additives, and curing process) ； Master the construction techniques properly, and pay attention to each stage of use based on the specific conditions of the process equipment and environment. 　　The use of epoxy resins generally involves the following steps: 1. Selection of the formula. 2. Surface treatment. 3. Adjust the glue. 4. Applying glue or filling with glue. 5. Fix the gel. 6. Curing. 　　The formula depends on the application; different use cases require different design approaches. The quality of formula design directly affects the performance of the final product. Surface treatment is important; otherwise, it will affect the bonding strength. When mixing the compound, it is important to first ensure that the resin, fillers, diluents, etc. are well blended together, and only then mix them thoroughly with the curing agent. When applying glue or filling with resin, care should be taken to minimize the inclusion of bubbles; especially during pouring, vacuum pouring is the best approach. The step of fixing the gel is very important for the bonding process, as epoxy resin bonding systems have a low initial viscosity; it is necessary to fix the materials to be bonded. When creating laminated products, pressure must also be applied until the gelation occurs, after which the pressure can be removed. The curing process must be carried out at the specified temperature and for the specified time in order to achieve the desired results from the cured product. 　　Products made from cured epoxy resin have many advantages, such as excellent mechanical properties, good electrical insulation, strong corrosion resistance, low shrinkage rate, high bonding strength, and ease of use. Therefore, it is widely used in the preparation of coatings, adhesives, laminates, castings, encapsulants, impregnating materials, etc., and plays a significant role in various industries such as machinery manufacturing, electrical and electronic equipment, transportation, petrochemicals, and national defense. As application areas evolve in these directions, epoxy resin systems have also made significant progress: saving energy and resources, with less energy required for curing and shaping ； Improve the operating environment to reduce and eliminate pollution ； Reduce labor intensity, improve production efficiency, enhance product performance, and meet the demands for higher precision, aesthetics, and practicality in products, while ensuring that prices remain in line with market requirements. To address this, there are now product systems that can cure at low temperatures while maintaining good heat resistance. There are also products designed to provide improved performance in various applications, as well as those that offer enhanced durability and resistance to harsh conditions.

In order to adapt to the ever-changing market, both epoxy resin manufacturers and those who produce curing agents and additives should pay attention to the specific developments in the following application areas:

1. Coatings
At present, the largest user of epoxy resins is still the coating industry. Although solvent-based epoxy coatings are still widely used, the product structure has changed significantly; they have evolved from traditional solvent-based forms to powder coatings, solvent-free coatings, water-based coatings, electrophoretic coatings, and UV-curable coatings. Due to changes in the product structure of the coating industry, the requirements for epoxy resins have also changed significantly. As we all know, traditional coatings mostly use epoxy resins as their raw material, whereas modern solvent-free coatings, water-based coatings, electrophoretic coatings, and UV-curable coatings generally do not use epoxy resins as their raw material. Although powder coatings account for about one-third of all epoxy coatings, most of the epoxy resins produced today are used in the manufacture of epoxy powder coatings. Epoxy hard resins account for a significant share of the market in the coatings industry, but the other two-thirds of ingredients in the coatings market represent a larger volume, and efforts should be made to capture that market as well. 　　Electrophoretic paints and weather-resistant coatings for automobiles. High-performance anti-corrosion coatings for ships, containers, oil pipelines, and gas pipelines. UV-curable coating for information material processing. The epoxy resins used by various application sectors are all evolving to meet the requirements of being solvent-free, water-based, low in viscosity, weather-resistant, and capable of rapid curing. Therefore, it is particularly important to develop bisphenol F-type, alicyclic, acrylic, and nitrogen-containing epoxy resins or their modified resins, as well as corresponding curing agents. 　　Everyone can see the rapid pace of development in high-tech products these days, and everyone wants to contribute to the high-tech sector in corresponding ways. For applications such as coatings for optical instruments, explosion-proof coatings for display tubes, and high-end floor coatings, epoxy resins are required to be colorless and transparent, while also possessing flexibility, wear resistance, and easy curing properties. This requires new epoxy coating systems to accommodate it. 　　2. Electrical and electronic industry The amount of epoxy resins used in the electrical and electronic industry ranks second. The electrical equipment industry is moving in the direction of large-scale power generation and high-voltage power transmission. Large nuclear and hydroelectric plants have rendered thermal power plants obsolete; moreover, wind and geothermal power plants will be built in the near future, leading to a transformation of the national power grid. All these impose stricter requirements on epoxy resins, as most of them are used in outdoor applications such as transformers, insulators, airfoil plates, cable terminals, etc., where the operating conditions are more severe. Epoxy resin systems are required to have high purity, good weather resistance, low moisture absorption, salt spray resistance, flame retardancy, and excellent overall mechanical and electrical properties. 　　The market in this area is largely dominated by foreign products, with only a few domestic companies capable of supplying small quantities. This should be the potential market for the development of China’s epoxy resin industry. 　　Other applications, such as adhesives, are also developing rapidly in the construction industry, but they will not be discussed in detail here. 　　As early as 1999, the Jiangsu Provincial Science and Technology Commission specified in its notice on the \"Implementation Opinions for Cultivating High-Tech Product Groups in Jiangsu Province\" that priority should be given to the development of self-developed solid-state interface circuit modules, as well as epoxy molding compound formulations and production technologies suitable for VLSII solid-state relays (SSRs) ； Production technologies for electronic-grade phenolic resins and epoxy resins ； ------Key technologies such as the production technology of epoxy molding compounds for sub-micron ICs. To this end, we must not only do a good job in developing our own industry but also pay close attention to the progress of related industries to achieve coordinated development.