Fabrication of Low-Density-Polyetylene-Based Transparent Hygroscopic Resin Dispersed with Nano-Sized Zeolite

Abstract

In order to realize transparent and hygroscopic films, it was shown that transparent hygroscopic films could be realized by surface modification of 4A zeolite with a median diameter of 50 nm to bring the refractive indices of the EVA resin and zeolite closer together. In order to make this technology applicable to general purpose, LDPE or LLDPE is suited as the base resin, and thin films should be produced by the inflation method. In this study, we attempted to realize a transparent moisture-absorbing film with LLDPE as the resin material and 50% nano-sized zeolite addition. However, the higher the zeolite content, the more difficult kneading and film-forming processes become. In fact, by using the blown film extrusion and cast film extrusion processes, it was impossible to form a film by tearing after extrusion when film processing was attempted by adding nano-sized zeolite with a surface modification treatment that produces high transparency. The results of our attempts to improve the problems from these results, it was found that a combination of a surface modifier that is highly effective in increasing the refractive index of the particles to increase their transparency and a modifier with excellent processability can be useful to facilitate kneading and molding. As a result, it was confirmed that resins containing 50 wt% surface-modified zeolite with such two surface modifiers could form 30 micrometer-thick films without dilution.