| Flat Panel Display such as liquid crystal display (LCD), plasma displaypanel (PDP) and organic light-emitting device (OLED) has advantages of lightweight, thin thickness, low energy, low radiation, free flicker and no harm tohealth. It has replaced cathode ray tube (CRT), an analogue type of display,gradually. Obviously, its production has become a huge industry. Film used inLCD panel is unable to meet the demands due to its surface hardness, scratchresistance and abrasion resistance. For that reason, coating should be added toimprove film’s surface performance. This paper aimed at developing a kind ofcoating for BOPET surface to make BOPET have a better performance ofhardness, scratch resistance, abrasion resistance and pliability and meet actualneeds. For UV curing technology’s feature of fast curing speed, saving energyand no volatile solvent, it was used to prepare coatings in this paper.The effects of photo-initiators, oligomers and active thinner on the basicproperties of coating were investigated respectively, furthermore, the optimalratio of these was determined according to practical requirements.Comprehensively considering the factors of coating’s pencil hardness, scratchresistance, abrasion resistance and adhesion force, hexa-functional polyurethaneacrylate CN9010NS and two-functional acrylate SR238NS were selected as mainoligomer and monomer separately. The weight ratio of CN9010NS to CN238NSwas1:1. For photo-initiators, influences of single photo-initiators and compositephoto-initiators on coating was compared. It was discovered that compositephoto-initiators had a better performance than single photo-initiators, and whenthe weight ratio of photo-initiator1173to photo-initiator184was5:3, thecomposite initiators could meet the requirements of pencil hardness, scratchresistance and abrasion resistance. Moreover, low-functional oligomers CN989and epoxy polyurethane arcrylate CN159NS could be used to improve coating’sperformance. The addition of low-functional oligomers would decline system’sconcentration of double bonds. Lower concentration of that would then reducethe crosslinking density after curing which increased coating’s pliability andadhesion. And adhesion force could be enhanced by epoxy polyurethanearcrylate since it had epoxy groups. For that reason, it was recommended to addappropriate content of CN989and CN159NS to strengthen coating’s pliabilityand adhesion force under the condition that pencil hardness, scratch resistanceand abrasion resistance were guaranteed. Besides, Tri-functional monomer SR351NS and high-functional monomer SR399NS acting as hybrid thinnerwould improve pencil hardness, cratch resistance, abrasion resistance as well asadhesion, but lower pliability. Therefore, hybrid thinner was used in this paperto improve coating’s performance under the premise that pliability was ensured.The basic properties of the UV-curing coating that this paper prepared weretested. And the result is that: pencil hardness is3H, scratch resistance is30under500g loading, abrasion resistance is0.3mg and the adhesion class is0.Test the coating prepared through FTIR, TG-DSC, UV-vis spectrum. And theresult shows that the coating prepared has excellent thermal properties, opticalproperties, chemical resistance, etc. |
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