Crosslinking agent, also known as crosslinking agent, is an important part of polyhydrocarbon photoresist. The photochemical curing effect of this photoresist depends on the crosslinking agent with dual photosensitive functional groups to participate in the reaction. , The cross-linking agent produces double free radicals after exposure, which interacts with polyhydrocarbon resins to form bridges between polymer molecular chains and become insoluble substances with a three-dimensional structure.
It is often a substance containing multiple functional groups in the molecule, such as organic dibasic acid, polyol, etc.; or a compound containing multiple unsaturated double bonds in the molecule, such as divinylbenzene and diisocyanate, N,N-methylene Base bisacrylamide (MBA) and so on. It can be fed together with monomers, after polycondensation (or polymerization) is cross-linked to a certain extent, so that the product becomes an insoluble cross-linked polymer; it can also retain a certain number of functional groups (or double bonds) in the linear molecule, and then add it Specific substances are cross-linked, such as curing of phenolic resin and vulcanization of rubber.
Crosslinking agents are mainly used in polymer materials (rubbers and thermosetting resins). Because the molecular structure of polymer materials is like a long line, it has low strength when not cross-linked, easy to pull off, and no elasticity. The role of the cross-linking agent is to create chemical bonds between linear molecules, making the linear molecules interact with each other. Connected together to form a network structure, which improves the strength and elasticity of the polymer material. The crosslinking agent used in the rubber is mainly sulfur, and an accelerator must be added.
1. Cross-linking and modification of various thermoplastics (polyethylene, polyvinyl chloride, chlorinated polyethylene, EVA, polystyrene, etc.). Thermal crosslinking is generally 1-3%, plus dicumyl peroxide (DCP) is 0.2-1%; radiation crosslinking is 0.5-2%, and DCP is no longer needed. After cross-linking, the heat resistance, flame retardancy, solvent resistance, mechanical strength and electrical properties of the product can be significantly improved. Compared with the peroxide system cross-linking alone, it can significantly improve the product quality and has no peculiar smell. It is typically used for polyethylene, polyethylene/chlorinated polyethylene, polyethylene/EVA cross-linked cables and polyethylene high- and low-foam products.
2. The assisted vulcanization of special rubber such as ethylene propylene rubber, various fluorine rubber, CPE (used with DCP, the general dosage is 0.5-4%), can significantly shorten the vulcanization time, improve the strength, wear resistance, solvent resistance and resistance Corrosive.
3. Crosslinking of acrylic and styrene ion exchange resins. Compared with divinylbenzene crosslinking agent, it has less dosage, high quality, and can prepare ion exchange resin with excellent anti-fouling, high strength, large pore size, heat resistance, acid and alkali resistance, and oxidation resistance. This is a new type of ion exchange resin recently developed at home and abroad with excellent prospects.
4. Modification of polyacrylate, polyalkyl acrylate, etc. Can significantly improve heat resistance, optical properties and process performance. Typically used for heat-resistant modification of ordinary plexiglass.
5. Modification of epoxy resin and DAP (diallyl phthalate) resin. It can improve heat resistance, adhesion, mechanical strength and dimensional stability. It is typically used for modification of epoxy potting materials and encapsulating materials.
6. Crosslinking and modification of unsaturated polyester and thermoplastic polyester. Can significantly improve heat resistance, chemical resistance, dimensional stability, weather resistance and mechanical properties. It is typically used to improve the heat resistance of hot-pressurized unsaturated polyester FRP products, and the use temperature of the modified products can reach above 180°C.
7. TAIC's own homopolymer-polytriallyl isocyanurate is a transparent, hard, heat-resistant, and excellent electrical insulation resin. It can also be used to bond glass and ceramics. It is typically used to manufacture multilayer safety glass.
8. Internal plasticization of polystyrene, copolymerization modification of styrene and TAIC, etc., can produce transparent and shatter-resistant products.
9. Protective agent for metal heat resistance, radiation resistance and weather resistance. TAIC prepolymer is baked on the metal surface, and its baking film has very good heat resistance, radiation resistance, weather resistance and electrical insulation. It is typically used in the manufacture of insulating materials such as printed circuit boards for microelectronics products.
10. Used as an intermediate for photocurable coatings, photoresist, flame retardant and flame retardant crosslinking agent. It is typically used to synthesize high-efficiency flame retardant TBC and flame retardant crosslinking agent DABC.