Study on formulation of UV coating

lencolo 2022-09-28 910

　　1, the limitation of photoinitiator, from the point of view of the system to think, UV resin, monomer activity

　　From the previous introduction of LED, we can see that the current high-power LED light source suitable for industrial production is limited in the UVA band, and the wavelength is mainly above 365nm. Once the capability boundaries of the LED light source have been established, the choice of initiators becomes very limited, with most initiators having very low molar extinction coefficients in the band above 365nm. In order to solve the low efficiency of LED photoinitiator is a problem, in addition to the development of the initiator itself, we should also think from the perspective of the system, the UV resin, monomer and initiator, and even some auxiliary additives, are integrated into a whole to study, improve the curing efficiency of LEDUV.

　　2, to achieve LED curing UV coating formula and coating process design (initiator, UV resin, monomer, temperature, surface dry, dry, pigment, filler influence)

　　In order to improve the absorption of long wavelength UV light by the initiator, it is often necessary to add benzene ring, N, P and other atoms in the molecular structure to improve the absorption of long wavelength UV light by the photoinitiator, but also bring the color deepening. And because the absorption efficiency of the initiator is too low, in order to improve the overall reaction speed of UV coating, need to add a large number of high reactive activity of UV resin and monomer, generally high energy acrylic UV resin and monomer, which will bring the film hardness and fragility of the problem, limited the application scope of the film.

　　Of course, the low molar extinction coefficient of LED photoinitiator also has its unique advantages. The high transmittance of UV light in the coating is conducive to the deep curing of thick coating.

　　3, different storage, transportation, construction conditions and construction technology on the performance requirements of the coating itself

　　In the field of painting, there are roller coating, spraying, spray coating and so on different construction technology, the viscosity of UV coating has different requirements, and different substrate, UV coating infiltration, adhesion and so on also have different requirements. The conditions of transportation and storage also have different requirements for the storage stability of UV coating itself, so when designing the formulation of UV coating, these factors should be taken into account.

　　4, different applications of film performance requirements

　　Because of different application fields, the performance of the film, such as gloss, color, hardness, toughness, wear resistance, impact resistance and so on, will have different requirements. Therefore, in the development of UV coating, we should take into account the balance between curing effect and film performance.