Study On Preparation And Properties Of Silicone And UV Optical Transparent Composite Film

Toughened glass protective films are made of toughened glass and PET double-side coated composite film.PET double-side coated composite film refers to pressure sensitive adhesive coating on the one side of PET substrate with low viscosity,optical transparency,self-adhesive and exhaust fast,for fitting the surface of the mobile phone,on the other side of the PET substrate with high viscosity transparent,fitting for toughened glass.The requirements of PET double-side coated composite film including viscosity,exhaust,adhesion,optical transparent properties,control of coating process are very high.Product quality and yield of domestic manufacturers are lagging behind manufacturers of Japan and Korea.The main purpose of this paper was to explore PET surface treatment technology used on PET double-side coated composite film,optical silicone pressure-sensitive adhesive with low viscosity and self-exhaust,optically transparent acrylic pressure-sensitive adhesive with low viscosity and UV curability,and the related technology of precision coating machine of PET double-side coated composite film.Silicone pressure sensitive adhesive was made up of 100 methyl vinyl silicone rubber(vinyl content:0.50-0.79%)with 20 poly(vinyl chloride)MQ resin,1.5 silicon hydrogen crosslinking agent and 1 platinum catalysts.High transmittance and low haze silicone pressure sensitive adhesive film was propared by coating on the PET substrate after corona and selecting the appropriate coating conditions.Then,on the other side of the silicone pressure sensitive adhesive film,UV curable polyurethane acrylate pressure sensitive adhesive was coated.The polyurethane acrylate pressure sensitive adhesive was composed of 100 parts of polyurethane acrylate prepolymer,50 diluent and 5 photoinitiator.When IBOA,DTMPTA and polybutadiene were mixed with 20:20:10,the performance of OCA was the best.The type of photoinitiators also affected the curing performance of OCA film.OCA ressure sensitive adhesive had the best curing effect and speed with mixture of 3 parts of 1000photoinitiators and 2 TPO photoinitiators.When UV curing energy was 2800mj/cm~2,OCA curing degree was 90%,meeting the needs of product and productive efficiency.For the coating process,maximum coating temperature was 150?.Because silicone glue needed sufficient time to flow and solvent evaporation,low temperature was essential at first,and the final temperature was not too high,so that the film would not have a sharp contraction and ensure smooth substrates.The thickness of silicone pressure sensitive adhesive should reach 30?m,so it could not be affected by small and medium impurity particles,meanwhile,the thickness of OCA should reach 50?m,which could fill the snowflake points or lines of the substrate of the adhesive layer to propare for high-end toughened glass protective film products without any apparent anomalies.There is little study on addition type silicone pressure sensitive adhesives in China.The research and industrial production of UV curing OCA are at the initial stage in China.In this paper,the research of adhesive formulation technology and precision coating technology was studied,which had a high application value.