Preparation Of UV-curable Organic-inorganic Composite Antireflective Coating

Antireflective coating(AR-coating) is an important optical film, which has been widely applied in the field of communication, electronics, construction, medical, biological and others. Nowadays, AR-coating was traditionally prepared by PVD, VCD methods, which need a complex process equipment, and the preparation condition was usually difficult to achieved. To overcome those disadvantages, Sol-Gol method was employed to characterize the film.In this paper, UV curing technology was introduced to overcome the disadvantages of the themal curing after spin-coating, which caused high energy consumption and inefficiency problem. Oganic-inorganic composite was designed to form the structure that sol particles were embedded in the resin film to enhance the strength of the antireflective coating. Specific major tasks include the following aspect:(1) Study on preparation of the SiO2 sol and AR-coatingUsing TEOS as precursors,preparation of alkaline and neutral SiO2 sol were studied by peptizing method. The impact of the adding amount of ammonia, water and aging time were emphatically investigated. The results show that the particles size of the sol gradually become larger by increasing the adding amount of ammonia. Changing the adding amount of ammonia from 5wt%o to 20wt%o, the average particles size has increased 6.2nm to 118.3nm and the uniformity of the sol has become poorer; The adding amount of water has the same influence on the SiO2 sol; The viscosity of the film increased rapidly by extending the aging time over ten days. The propertis of the coatings which prepared with different S1O2 sol was measured. The results show that the amount of the microporous in the coating has reduced through increasing the particles size of the sol.On the contrary, the mesoporous and pore size has become larger. The results also show that the film with larger particles has a better optical performance.(2) Study on preparation of photosensitive resin filmThe photosensitive resin was prepared by using low viscosity monoacrylate oligomer as oligomer, ODA as monomer. The impact of the photoinitiator’s categories, the adding amount of the potoinitiator and the UV-curing time were emphatically investigated. The results show that BP was the best photoinitiator. and its adding amount was 3wt%. The optimum UV-curing time was 7 min. The film has the best optical performance while the amount of the oligomer was 20wt%. The hardness of the film has increased and the Oxidation resistance become poorer in pace with increasing the adding amount of oligomer.(3) Study on preparation of organic-inorganic composite antireflective coatingUsing the SiO2 sol and photosensitive resin as the tow phase in the organic-inorganic composite system, double-layer coating and monolayer coating were prepared by spin-coating. Two types of the AR-coating were characterized by using several methods. The results show that the transmittance was improved over 4% in all double-layer AR-coatings while the concentration of the vol was 2wt%.The mechanical performance of the double-layer was below 3B. The peak value of the transmittance in the compound monolayer AR-coatings was 95.4%while the proportion of the resin was 40wt%.In that condition, the film has the best mechanical performance at 2H.