How are black spots detected in solid petroleum resins?
The curing agent can be divided into catalytic type (such as three boron trifluoride amine complex, tertiary amine) and co reaction type (such as polyamine and anhydride). Catalytic curing agent of epoxy resin by homopolymerization, the dosage can be determined experimentally; total reactive curing agent is active hydrogen containing multifunctional reagent, it is the calculation of active groups with resin by chemical (epoxy and hydroxyl) reaction. Curing agent up to 300 kinds. For example, aliphatic polyamine, low molecular polyamide, etc., can be cured at room temperature epoxy resin; anhydride, aromatic polyamine and so on, you need to rely on heating to complete the curing reaction.
The production of two routes with a solid resin with higher molecular weight of DPP and ECH in direct reaction of alkali and molecular weight are regulated by the ratio of two kinds of raw materials; the liquid resin as raw material, in the presence of a catalyst with bisphenol A chain expansion resin with high degree of polymerization, the molecular weight is adjusted by molar ratio the liquid raw material resin and bisphenol A. By using this improved process, the resin grade with higher molecular weight can be directly manufactured. Curing: when using epoxy resin, it is necessary to add a chemical active agent, that is, the curing agent, under appropriate conditions, the linear epoxy resin cross-linking curing into large network molecules, to show its inherent good characteristics.
The largest use of epoxy resins is for protective coatings such as automotive primers, finishes, marine coatings, internal coatings and finishes for various tanks and other products.
