The UPR light curing powder coatings R & D progress
Now the increasingly high demand for environmentally friendly, waterborne coatings, powder coatings, high solids coatings, and radiation curable coatings and other energy-saving, low pollution paint varieties of universal concern, a major paint company focused on research projects and product development. Conventional powder coatings for metal materials because of its high curing temperature only, while the UV curing powder coatings because of their low curing temperature, the apparent flatness can be applied to various types of thermal materials. Also a small amount for metal, metal / plastic composite, reported in the paper substrate. UV-curable powder coatings for wood, plastic, MDF board reported up to. Light-cured powder coating is a powder coating and light curable coatings respective advantages of each other, emerging coating. Light-curing coatings compared to other powder coating can be cured at lower temperatures, suitable for wood, plastics and other heat-sensitive substrate coating; combined with light curing speed, automated assembly line coating, developed very quickly, the annual growth rate remained 12 to 15 percent. UV-curable powder coatings commonly used resin: epoxy acrylate, acrylic resin, unsaturated polyester, polyester acrylate, polyether acrylate. Although the above-mentioned resin systems meet the basic requirements, but it is difficult to reach the ideal fluidity at low temperatures. People find new ways to solve this problem, ie, crystalline / amorphous system and semi-crystalline / amorphous system. Crystalline / amorphous system is a mixture of crystalline compounds and non-crystalline resin. Others study glyceride, and the terminal carboxylic crystalline polyester methacrylate preparation of radiation curable powder coatings.
DSM has developed a polyurethane powder coating systems based on unsaturated polyester of maleic acid and vinyl ether functional group (MA / VE) of wood and plastic. The system consists of two kinds of polymer, based on electron-rich vinyl ether functional group, and poor e-maleic acid cool groups 1:1 copolymerization UV curing. The system contains a matching of maleic vinegar-based and vinyl ether, the advantages of the two components under controlled conditions does not occur Homopolymerization, and powder coating is thermally stable. Polymerization of Zhejiang University School of materials of the State Key Laboratory of the light curing of unsaturated polyester and acrylic epoxy powder coating matrix resin, the structure of the two matrix resin, the ratio of light-curing coating degree of curing and its performance. The results show that the curing degree of influence of solvent resistance, adhesion, film hardness and impact strength of the key, the appropriate n (UP) / n (EA), 1:1, and its degree of curing should be greater than 95% up to 99 %. Determination of coating curing, analysis of the relationship between the degree of curing of the resin structure, coating formulations, curing conditions, about 50% of the unsaturated polyester coating formulations of the system of double bond content of the total content is more appropriate, available The high degree of curing and good performance of the coating; analyzed the relationship between film properties and film curing, found that the degree of curing is a key factor affecting the film properties. Degree of curing more than 95%, the coating adhesion, hardness, solvent resistance and impact strength have improved greatly; developed unsaturated polyester, acrylic epoxy matrix resin can be used as UV-curable powder coatings This film properties is good.
On light curing adhesives. Light curing technology of polymer materials with rapid curing, environmentally friendly, energy saving, and easy, rapid development and great progress in the field of coatings, inks, electronic packaging, adhesives, etc., the annual growth rate of up to 25% has formed a new industry . Chenguang Chemical Research Institute has developed three kinds of light-cured resin preparation process, the modified system on the performance of the photosensitive resin. Unsaturated polyester resins (UPR) with low viscosity; hard epoxy acrylate resin (AE); carboxyl-terminated polyether (CTPE) modified epoxy acrylate (AEPE) effectively improve the toughness of the material; urethane acrylate The resin can get soft until the strength of cured, containing polyether chains toughening modifier obtained modified unsaturated resin UP35, 35% of the monomer diluent styrene was prepared by liquid viscosity 300mPa.s around, good toughness, and strong bonding. Single component of the resin-based material system photosensitive the glue GUV1 curing glue the GUP) 35 good optical performance, the firm bonding of optical components and easy to dismantle the plastic repair can be used as an optical adhesive. Another gel coat resin as special varieties of unsaturated resin, but also to strengthen the UV Curing of Chemistry and Chemical Engineering, Henan University with isophthalic acid, phthalic acid and its two mixtures (between phthalic anhydride molar ratio of 4 : 1) with the diol (propylene glycol and diethylene glycol, the molar ratio of 4:1) was synthesized by three kinds of gel coat resin, the resin added to the mass fraction of 1% benzoin ethyl ether photoinitiator UV irradiation for 30 minutes can be cured.