Abstract
We have investigated the narrow gap filling by liquid epoxy resins containing silica particles at the volume fractions of 0.30, 0.40, and 0.49. The penetration of these liquid resin composites into a narrow gap between two parallel glass plates was observed. Addition of silane coupling agents reduced the filling time more significantly at the higher volume fraction of particles. This behavior was explained by the Washburn equation with the effects of the coupling agents on the surface tensions, contact angles, and shear viscosities of the liquid resin composites, which were experimentally measured. The narrow gap filling was theoretically described by a modified Washburn equation, where the non-Newtonian behavior of the liquid resin composites was considered by way of the shear-rate-dependent viscosity. The results from the modified Washburn equation semiquantitatively agreed with those from the experiments.
