UV metal coating
UV vacuum electroplating coating is mainly composed of UV curing resin, monomer, photoinitiator, pigment, leveling agent, adhesion promoter, etc. According to the division of application surface, it is mainly composed of UV vacuum electroplating primer and UV vacuum electroplating topcoat. In order to match the modern new electroplating technology, some of them also have vacuum electroplating coating.
The effect of primer UV vacuum coating coating primer is coated on the surface of the plastic substrate coating, its role is to close the plastic substrate, to prevent the volatile substances in the substrate during vacuum plating affect the quality of the coating.Plastic surface is rough, through the primer coating can obtain smooth smooth mirror effect, is conducive to obtain a thicker and uniform vacuum metal coating, show higher metallic luster and reflection effect.For some substrates with lower polarity, better adhesion properties can be obtained by vacuum electroplating of metal coating through primer transition.The primer also ACTS as a thermal buffer for some plastic substrates with poor heat resistance.
Primer coating primer UV vacuum plating of the above, requires a primer must be on the plastic base material and vacuum coating metal layer, good adhesion, is both good and weak polarity plastic coating substrate adhesion is good, and has good adhesion with polarity metal, the plastic coating is more demanding than simple, also indirectly proves that most of the UV vacuum plating resin are same or higher than applicable to simple UV plastic coatings.
At the same time, in order to guarantee the high gloss and mirror effect of the metal coating, the primer must have excellent leveling performance.In addition, the primer curing should not have volatile small molecules, otherwise it will destroy the quality and performance of the metal coating, so the primer formula of macromolecular quantization is an important consideration.For some of the heat resistant base material, UV primer with its thermal performance is also very important, such as heat resistance of BMC requirements up to 180 °.In addition, in order to prevent coating cracking or jumping off, the system flexibility of primer also appears particularly important.
Primer of formula design according to the performance requirements of the UV vacuum coating primer, primer formula on choosing oligomer to fully consider the flexibility, adhesion, flowing property and molecular weight, so the need to give attention to two or more things, generally choose two or three faculties of polyurethane acrylic resin as the main body, such as the market popular 6158 and UA202, also considering the cost and performance factors, tend to select certain or polyester epoxy resin using collocation, monomer with TP commonly as the priority, the initiator for the longer wavelengths is first selection, the other the right amount of phosphate and adhesion promoter can be appropriate to add.
The function of finish and requirements UV vacuum electroplating finish is coated on the vacuum coating metal coating, it plays a protective role in the coating and a certain decorative role.So the surface paint requires good adhesion to the metal coating film, to have enough performance to resist the external friction, scratch, scratch and other external forces, and provide a certain resistance and resistance.In addition, most of the topcoat or coating is the need to add color modification, the entire coating system of wettability requirements of the color filler is also very high.
Finish the formula design of UV vacuum plating finish and primer is different, in order to assure the mechanical properties of coatings, tend to choose high some functionality resin to compatibility, and give full consideration to add color, will allow to add high functionality to improve wear resistance of resin, in addition, for pigments added convenience in order to guarantee system, polishing performance good resin is preferred, Such as the import of Changxing chemical 6071 and domestic Qianchen material UA378, Europe and the United States have a good material selection..In terms of additives, HEMA auxiliary properties can be selected in small amounts on the premise of ensuring the performance.