Preparation of siloxymethyl-modified silicone acrylate prepolymers with UV/moisture dual curability for applications in anti-smudge and anti-fingerprint coatings

Abstract

UV-curing technology is an efficient, energy-saving and eco-friendly technology, which has been widely used in industrial production and daily life. However, UV curing is difficult to achieve with thick coatings, coloured coatings, and shadowed regions of coatings, which greatly limits the applicability of this process. As reported herein, UV/moisture dual curable siloxymethyl-modified silicone acrylate (SMSA) prepolymers were synthesized through the two-step sequential hydrosilylation of pentaerythritol tetraacrylate (PETTA), hydride-terminated polydimethylsiloxane (H-PDMS) and trimethoxysilane (TMOS). The prepolymer contains UV-curable acrylate groups and moisture-curable siloxymethyl groups, and thus it can be readily cured via exposure to UV light, moisture, or a combination of UV light and moisture. Combining the advantages of UV and moisture curing, the prepolymer is capable of curing rapidly and overcomes the problem of UV curing about shadowed areas and thick coatings. This combined UV/moisture dual curing process also solves the problem of oxygen inhibition and poor adhesion of conventional UV-curable silicone materials. The properties of UV/moisture dual cured coatings were characterized and found to exhibit excellent transparency, heat resistance, as well as hydrophobicity. The transparencies of these coatings are over 93% even the thicknesses are up to 100 µm. The coatings remain stable when temperatures reach up to 296.5 and 317.2 °C. The water contact angles of coatings are between 97° and 103°, and surface energies of the coatings vary from 25.43 to 21.27 mN/m. The UV/moisture dual cured coatings also have excellent resistance to smudge and fingerprints. Therefore, they will be suitable for the preparation of anti-smudge and anti-fingerprint coatings.