UV curing refers to the UV curing in the radiation curing system (referred to as UV curing). Radiation curing technology is a new green technology, which refers to the process of instant polymerization and cross-linking curing of liquid phase system through ultraviolet light, electron beam and r-ray irradiation. It has the advantages of energy saving, high efficiency, excellent coating performance, glue saving, safety and environmental protection, high brightness, long duration, etc. Natural stone itself has some inherent defects, such as pits, cracks, uneven plates, etc. (both granite and marble exist).
Construction method characteristics:
1) Excellent coating performance: UV curing coating has excellent performance, high gloss, high hardness, and good chemical resistance. Effectively improve the repair quality of stone holes.
2) Safety and environmental protection: Because the UV curing speed is very fast, the emission of organic solvents in the air is reduced to zero, which is safe and environmentally friendly.
Process principle:
UV coatings are UV curable coatings. After the UV curable coatings are irradiated by UV light, the photoinitiator first absorbs the UV radiation energy and is activated. The electrons in the outer layer of its molecules jump and generate the active center in a very short time. Then the active center acts with the unsaturated groups in the resin, causing the double bonds in the light-emitting curing resin and the active diluent molecules to be disconnected, resulting in a continuous polymerization reaction, so as to cross link each other to form a film. The study of chemical kinetics shows that the mechanism of UV curing UV coatings is free radical chain polymerization. First, the photoinitiation stage; The second is the chain growth reaction stage. In this stage, as the chain growth proceeds, the system will be cross-linked and solidified into a film; The Z post chain radicals complete chain termination through coupling or disproportionation.
1. Oligomer
Prepolymer, also known as oligomer or resin, is the skeleton of UV glue. It mainly refers to a class of molecular polymers with unsaturated double bond structure. It further reacts and forms cross-linked curing body after expansion, which endows materials with basic physical and chemical properties. For example, viscosity, tensile strength, shear strength, hardness and compliance.
2. Monomer
Monomers, also known as reactive diluents, are mostly small molecules containing one or more double bonds, which are mainly used to adjust the viscosity of the system and participate in polymerization, but also have an impact on the polymerization rate and material properties. Monomers can be divided into monofunctional monomers, bifunctional monomers and multifunctional monomers according to the degree of functionality. Monofunctional monomers are beneficial to enhance the flexibility and adhesion of colloid; Difunctional monomers and multifunctional monomers not only act as diluents, but also act as cross-linking agents. They have an important impact on hardness, toughness and strength.
3. Photoinitiators)
Photoinitiators are active intermediates that can absorb ultraviolet or visible light and produce polymerization initiating ability through chemical changes. They are key components of the photopolymerization system and play a decisive role in the sensitivity (curing rate) of the UV curing system. Photoinitiators include free radical photoinitiators and cationic photoinitiators, which are applied to free radical systems and cationic systems respectively.
Post time: Nov-24-2022