セルロースナノファイバー添加アクリル中間膜を用いたガラス/ポリカーボネート積層安全ガラスの耐衝撃性評価

抄録

Safety glasses used in machine tools require good impact and solvent resistances and high transparency. These requirements can be satisfied by glass/polycarbonate (G/PC) laminated safety glass incorporating acrylic interlayer (ACIL). Recently, there has been an increasing demand for higher impact resistance and light-weight G/PC laminated safety glasses because of high-speed and precision machining. To improve the impact resistance of G/PC laminated safety glass under the same laminate configuration, enhancement in the energy absorption performance of ACIL is required. For the same, in this study, cellulose nanofibers (CNFs) having a diameter of a few dozen nanometers and high aspect ratio were focused as a filler. Addition of CNFs to ACIL is expected to enhance the energy absorption ability of the G/PC laminated safety glass owing to the internal friction at the interface and microcracking near the CNFs, with retaining the transparency of ACIL. In this study, ACIL with CNFs (CNF/ACIL) was fabricated by using a bead mill and tensile tests were performed on the material. In addition, drop-weight tests were performed on the G/PC laminated safety glass incorporating CNF/ACIL to evaluate its impact resistance. Results from the tests showed that the stress at 300% strain of CNF/ACIL exhibited a maximum value when the CNF concentration was 0.1 wt% and decreased monotonically with further increase in the CNF concentration. Further, the G/PC laminated safety glass incorporating CNF/ACIL showed an enhanced impact resistance when the CNF concentration was not more than 0.5 wt%.