Preparation And Application Research On Heat/UV Dual-curing Heat Transfer Coating

Domestic transfer products commonly use thermoplastic material as the heat transfer protective layer to supply protection to the pictures on the surface of the products, but the protection level is limited because of its poor mechanic performance and resistance to chemical reagent. This thesis adopted Heat/UV dual-curing material as the heat transfer protective layer which not only emerged in the advantage of UV-curing technology like high curing speed, high mechanical performance and good resistance to chemical reagent, but also solved various technology problems when pure UV-curing coat was applied in heat transfer technology. The Heat/UV dual-curing coat promises the strong protection and decoration to the pictures on the surface of products, which enhances the use value and added value of heat transfer products and broadens the applying scope of heat transfer technology.First, the Heat/UV dual-curing protective layer was prepared and the application mechanism of Heat/UV dual-curing protective layer was introduced. Heat/UV dual-curing heat transfer protective layer uses a special curing way which means the coat first cures through heat and then cures by UV light. The heat curing process is that heat curing agent’s-NCO reacts with-OH from UV-curing resins and monomers, then cured to be the protective layer existed in the heat transfer film. After the pictures in the ink layer of the heat transfer film are transferred to the surface through heat and pressure, protective layer becomes the top layer on the surface of the products. Then letting the photo initiator release free radical through UV radiation triggers the reaction between the double bonds in UV-curing resins and monomers, leading to a more compact structure which supplies the strong protection to the pictures on the surface of the products.Secondly it introduced the technologies and analyses the related problems when Heat/UV dual-curing protective layer was applied in heat transfer technology. The technologies includes heat transfer films’ producing and applying technologies. The technology problems discussed are indeed the problems between protective layer and release layer, ink layer, coherence layer, aluminizing layer.Finally the performance of Heat/UV dual-curing protective layer after transferring to the products would be discussed. First through comparing Heat/UV dual-curing protective layer with transitional thermal plastic protective layer, thermosetting protective layer and pure UV-curing protective layer, it finds that Heat/UV dual-curing protective layer is not only better than transitional protective layer or thermosetting protective layer in the protective performance but also more suitable for the heat transfer technology than pure UV-curing protective layer which proves that Heat/UV dual-curing protective layer is the most ideal material to be the protective layer of heat transfer film both in the protective performance and the adaptability of heat transfer technologies. Then the elements influences the film’s performance would be discussed. These elements include UV-curing resins, monomers, the content of heat curing agent and the thickness of protective layer. The research shows that the kinds of UV-curing resins and monomers has a big impact on the coating’s protective performance like hardness, abrasive resistance, resistance to chemical reagent etc. With the increase of the coating’s cross linking density, the coating’s protective performance will be enhanced. And whether the UV-curing resins and monomers have-OH or not determines the protective layer’s adaptability to heat transfer technologies like aridity. According to the results above, Polyurethane acrylic ester and PETA are respectively the ideal UV-curing resin and monomer of protective layer material. The content of heat curing agent has not big influence to the protective performance of coating, but a big impact on the adaptability to heat transfer technologies. When the content of heat curing agent comes too low, the coating is not totally dry which will leads to adhesive problems. When the content of heat curing agent goes too high, it nay leads to the technologies problems like imperfect of side shearing or crack of corner side. Therefore,30%is the most proper content of heat curing agent to gain good protective performance and adaptability of heat transfer technologies. What the thickness influence the coating’s protective performance are mainly abrasive resistance and appearance. With the increase of coating’s thickness, the abrasive resistance and fullness, but the leveling effect will drop obviously because it needs to recoat if the thickness continues to increase. Taken together,4μm-6μm are the most proper thickness for protective layer.