poxy resin, phenolic resin and unsaturated polyester resin is referred to as the three general type thermosetting resin. They are thermosetting resin in the amount of the largest, most widely used varieties. Epoxy resin containing unique epoxy, and the light base, ether bond and other active groups and a polar group, which has many excellent properties. Compared with other thermosetting resin, epoxy resin types and grades of up to, the performance of different. Epoxy resin curing agent type are more, plus numerous agent, modifier, additive, can undertake various combination and assembly. In order to obtain all kinds of performance, features and cured epoxy curing system. Hardly able to adapt and meet various use performance and process performance requirements. This is the other thermosetting resin can not be compared.
1, epoxy resin and its curing property characteristics
( 1) the mechanical properties of high. Epoxy resin has a strong cohesive force, the molecular structure of dense, so its mechanical properties is higher than that of phenolic resin and unsaturated polyester universal type thermosetting resin.
( 2) bonding performance. Epoxy resin curing system of epoxy is very active, hydroxyl and ether, amine, ester bond bond polar group with epoxy resin cured with high adhesive strength. Plus it has a high cohesive strength and other mechanical properties, so its adhesive properties particularly strong, can be used as a structural adhesive.
( 3) curing shrinkage of small. Generally 1% ~ 2%. Is a thermosetting resin curing shrinkage rate the smallest one species ( phenolic resin 8% ~ 10%; unsaturated polyester resin 4% ~ 6%; silicone resin 4% ~ 8%). Linear expansion coefficient is very small, typically 6 x 10-5 / c.. So the product size stability, small internal stress, not easy to crack.
( 4) good technology. Epoxy resin curing basically does not produce low molecular volatile, so low pressure molding or contact pressure molding. Formulation design of great flexibility, can be designed to fit the various technical requirements formula.
( 5) good electrical properties. Dielectric properties of thermosetting resin is one of best varieties.
( 6) good stability. Different alkali, salt and other impurities in the epoxy resin is not easy to deteriorate. As long as the proper storage ( seal, not damp, not meet the high temperature ), the storage period of 1 years. After passing inspection can use if extended. Epoxy curing agent has good chemical stability. The alkaline and acid, salt and other corrosive performance superior to the unsaturated polyester resin, phenolic resin, thermosetting resin.
( 7) the heat resistance of epoxy resin cured is generally 80 to 100 DEG c.. Epoxy resin heat resistance varieties of up to 200 DEG C or higher.
(8 ) in the hot lies resin, epoxy resin and its curing the best comprehensive performance.
In 2, the application of epoxy resin characteristics
( 1) has a great recipe design flexibility and diversity. According to different performance and process performance requirements, design targeted the best formula. This is the application of epoxy resin in one of the major characteristics and advantages. But the best formula has a certain scope of application ( conditions ), not in any conditions and any conditions of use are advised to use. That is to say no" universal" the best formula. According to different conditions, the design of different optimum formula. Due to the different formulations of the curing system of epoxy resin curing principle is not exactly the same, and epoxy resin curing process, namely the curing conditions on the structure and properties of epoxy resin cured great influence. The same formula under different curing conditions, the properties of the obtained product can have very big difference. So it correctly make the best material formulation design and process design is the key of application technology of epoxy resin, is also a technology secret place. To be able to produce and develop their own desired properties of epoxy material, must design the special formula and process conditions. Therefore, we must deeply understand and master the epoxy resin and its curing agent, modifier on the structure and properties between them, the reaction mechanism and the structure and properties of epoxy resin cured effect. Such ability in materials design and process design of handy, handle very skillfully, obtain the best scheme, production and development of the best performance, the lowest cost epoxy materials and products.
( 2) the different curing system of epoxy resin in low temperature, room temperature, respectively in temperature or high temperature curing, can in the wet surface or in water curing, quick curing, can also slow curing, so that construction and manufacturing process required the adaptability is very strong. Epoxy resin can be low pressure molding or contact pressure molding, thus can reduce the molding equipment and tooling requirements, reduce investment, reduce cost.
( 3) in the three general type thermosetting resin, epoxy resin high prices, resulting in the application by a certain impact. However, because of its excellent performance, and is mainly used for applications requiring high performance, especially for the comprehensive performance requirements of high field.