As early as 189 1, Lindmann of Germany reacted hydroquinone with epichlorohydrin, condensed it into resin and cured it with anhydride. But its use value has not been revealed. In 1930, Pierre Castan of Switzerland and S.O.Greenlee of the United States made further research, and cured the above resins with organic polyamines, which showed high adhesive strength and attracted people's attention. Broadly speaking, epoxy resins can be synthesized from parent compounds containing alkenyl groups or active hydrogen atoms. The epoxidation of olefins was first reported in the early 20th century, but it was not until the mid-1940s that Swern and his partners in the United States Department of Agriculture began to study the epoxidation of polyunsaturated natural oils. This technology was only applied to the production of monoepoxides with relatively high molecular weight, which aroused extensive industrial development interest. It was not applied to the synthesis technology of epoxy resin until 10 years later. In the mid-1920s, the reaction product of bisphenol A and epichlorohydrin was reported. After 15 years, the production technology of unstable epoxidized fatty amine intermediates was created. Germany1933 SCLACK [1] studied the separation technology of modern bisphenol A epoxy resin from bisphenol A. Although SCLACK reported the reaction of epoxides with organic acids, inorganic acids, amines and thiols one year later, it was Castan of De Trey Freres in Switzerland and Greenlee of Devoe & Rayno 1DS in the United States who confirmed the industrial value of bisphenol A epoxy resin. 1936, amber epichlorohydrin-bisphenol A resin was produced in Castaing, and reacted with phthalic anhydride to produce thermosetting products with industrial significance, which were used for casting molding products. At the beginning of 1939, Greenlee also independently produced high molecular weight bisphenol A epichlorohydrin resin, which was used in advanced thermosetting coatings. From 1937 to 1939, Europe tried to fill teeth with epoxy resin, but it was unsuccessful. In addition, before the Second World War, epoxy resin technology had not been fully developed. Shortly after the war, Devoe & Rayno 1DS began trial production of coating resin, and CIBA company got permission from De Trey Freres to further develop liquid epoxy resin for liquid coatings, laminates and adhesives. Castan's basic patent authorization in 1943. However, Devoe—Raynolds Company of the United States completed the first industrial manufacturing of epoxy resin in 1947, which opened the technical history of epichlorohydrin-bisphenol A resin, and the epoxy resin began to be industrialized, which is considered to be a technological progress superior to the old phenolic resin and polyester resin. The performance of this resin is almost comparable to that of most other thermosetting plastics, and it is better than phenolic resin and polyester cheese in some special applications. Soon, CIBA (Ciba Switzerland, Shell and Spleen in the United States and Dow began the industrial production and application development of epoxy resin. In the late 1950s, two American companies, Ciba and Devoe—Raynolds, continued to study glycidyl ether epoxy resin, while Shell Chemical Company only provided epichlorohydrin. The Plastics Department of Union Carbide Company first manufactured phenolic resin and bisphenol A, while Ciba and Shell of Europe concentrated on developing epoxy resin.
In the summer of 1955, four basic epoxy resins obtained manufacturing licenses in the United States, and Dow Chemical-—cal Company and Reichho 1d Compound Company established epoxy resin production lines. At the same time of the production and application of ordinary bisphenol A epoxy resin, some new epoxy resins have also come out one after another. For example, 1956, Union Carbide Company of the United States began to sell alicyclic epoxy resin, 1959, and Dow Chemical Company produced phenolic epoxy resin. About 1960, Koppers, co. produced o-cresol formaldehyde epoxy, and in early 1965, Ciba began to produce and distribute this resin. During the period of 1955 ~ 1965, the quality of epoxy resin was obviously improved, and bisphenol A epoxy resin had all grades of average relative molecular weight. Phenolic epoxy resin shows obvious superior performance in high temperature application. Shell Chemical Company and United Carbon Plastics Company produce multifunctional phenol glycidyl ether and other special heat-resistant resins, and manufacturers also provide aliphatic polyol-epichlorohydrin resin. Unio Carbide developed aminophenol glycidyl ether resin. 1957, a patent on the synthesis process of epoxy resin came out, which was applied by Shell Development Matt Company. The patent studied the application process of curing agent and additive, and revealed the application of curing epoxy resin.
The epoxy resin synthesized by peracetic acid method was first introduced by Union Carbide Company of the United States in 1956 and resold to Union Carbide Plastics Company in 1964. In Europe, the industrialized alicyclic epoxy resin came out in the early 1960s, and was introduced to the United States through Ciba Company on 1963. Ciba introduced multifunctional epoxies of various carbon chain plastics at 1965, and FMC CORP began to distribute epoxidized polybutadiene around 1960. In the mid-1970s, the United States, Canada, Britain, Switzerland, West Germany, Belgium, Argentina, Mexico, Poland, Czechoslovakia and the Soviet Union began to manufacture bisphenol A epoxy resin and some new epoxy resins. In the 1970s, electronic applications with low chlorine content began, and aging-resistant resins such as five-membered ring epoxy and hydrogenated bisphenol A epoxy, and flame-retardant epoxy resins such as tetrabromobisphenol A epoxy and bromine-containing epoxy compounds were developed successively. In 1980s, in order to meet the needs of composite materials industry, a new multifunctional epoxy resin with compound amine and phenolic structure was developed. Recently, water-based epoxy resin and fused ring temperature and humidity resistant epoxy resin have been developed. Due to the increase of epoxy resin varieties and the development of application technology, the application of epoxy resin in the fields of electrical insulation, anti-corrosion coatings, metal structure bonding and so on has made breakthrough progress. At present, its variety, application and development are still very active. Since 1960, hundreds of epoxy resins have been industrialized, and 40 ~ 50 epoxy resins with different structures have been commercialized or provided by pilot plants. At the same time, industrial curing agents with a ratio of 100 and many modifiers and diluents are suitable for them, which means that they are in the ascendant.
The development of epoxy resin in China began with 1956, and it was first successful in Shenyang and Shanghai. 1958, industrial production began in Shanghai and Wuxi. In the mid-1960s, we began to study some new alicyclic epoxy resins: phenolic epoxy resin, polybutadiene epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin and so on. By the end of 1970s, China had formed a complete industrial system from monomer, resin, auxiliary materials, scientific research, production and application.
Epoxy resin has excellent physical and mechanical properties, electrical insulation, drug resistance and adhesive properties, and can be used as coatings, casting materials, molding materials, adhesives and laminated materials, which directly or indirectly penetrate into all aspects of the national economy from daily necessities to high-tech fields. For example, epoxy resin is widely used in composite materials in aircraft and spacecraft, packaging materials for large-scale integrated circuits, insulation materials for generators, coatings for steel and wood, adhesives for machinery and civil buildings, and even inner wall coatings for canned food and metal anticorrosive electrophoretic coatings. It has become an indispensable material in the development of national economy. Its output and application level can also reflect the developed degree of a country's industrial technology from one side.