The Action Mechanism of Reactive Film Adhesive
Bonding refers to a state in which two surfaces are bonded together by chemical, physical, or both forces. The reactive film adhesive must first adhere to the surface of the object to be adhered due to the adhesive force between the two phases, which comes from the secondary adhesive force or the primary adhesive force.
Bonding refers to a state in which two surfaces are bonded together by chemical, physical, or both forces.reactive film adhesiveIt must first adhere to the surface of the object to be adhered, due to the adhesive force between the two phases, which comes from the secondary adhesive force or the primary adhesive force.
Cohesive force: A state in which particles in a single substance are bound together by primary bond forces (including ionic bonds, covalent bonds, coordination bonds, metallic bonds, etc.) and secondary bond forces (including van der Waals forces and hydrogen bonds). The cohesive force of the reactive film adhesive is related to the intermolecular force, relative molecular weight, degree of crosslinking, crystallinity and molecular entanglement.
1. Reactive Film Adhesive Requirements
1. In any state, the coating should be liquid;
2. The surface of the object to be bonded can be fully spread and wetted;
3. It must be able to transform the liquid into a solid or gel state in some way to form a tough and stable reactive film adhesive layer;
4. It should have a certain strength after curing. Reliable connection, stress transmission, resistance to damage;
5. It can withstand temperatures above 0°C and can withstand a certain period of time.
Classification of 2. reactive film adhesives
Appearance classification:Type of solvent;Emulsion type (water based);Paste;Solid;Membrane type.
3. curing method
Water-based evaporation type, solvent evaporation type, hot melt type, chemical reaction type, pressure sensitive type.
Basic composition of adhesive
1. The basic composition of the adhesive
The components of the adhesive include a substrate, a curing agent, a solvent, a plasticizer, a filler, a coupling agent, a crosslinking agent, an accelerator, a toughening agent, a tackifier, a thickener, a diluent, an antioxidant, a polymerization inhibitor, a flame retardant, an initiator, a photosensitizer, an antifoaming agent, a preservative, a stabilizer, a complexing agent, and an emulsifier.
2. Substrate type
The substrate is the main component of the adhesive, the main agent or the main polymer, which plays a bonding role. Depending on the chemical composition, the base material is derived from inorganic compounds and organic compounds. Organic compounds are polymer-based materials used in polymer synthesis.
2.1 common organic compounds
Thermosetting synthetic resins: phenolic resins, epoxy resins, amino resins, polyurethane resins, unsaturated polyesters and acrylic resins.
Thermoplastic synthetic resin: rubber-based materials, natural polymer materials, water-based latex-based materials
rubber-based adhesive
2.2 bonding substrate selection principles
The adhesive is selected according to the application object, application occasion and application performance. At the same time, the molecular structure of the molecular matrix is closely related to the adhesive properties.
1) Polarity related polymer materials
2) Crystallization characteristics of polymer materials
3) Molecular weight of polymer materials
The ground state raw materials can be converted into linear polymers or network polymers through chemical reactions, polymerization, condensation or cross-linking reactions, which is a material with mechanical strength and stability of adhesive joints.
Related News