Gen Komiya

Improving Epoxy-based Insulating Materials with Nano-fillers toward Practical Application

A primary concern in recent nanocomposite research is practical application. In this study, various kinds of epoxy-based nanocomposites were made and their properties evaluated to determine their applicability as insulating materials for heavy electric apparatuses. Experimental results demonstrated that nano-fillers enhance insulation breakdown properties in nanocomposites. Moreover, nano- and micro-filler combinations were adopted as an approach toward practical application of nanocomposite insulating materials. These nano- and micro- filler mixed composites had the same low thermal expansion as aluminum, and insulation breakdown properties superior to those of conventional insulating materials. Consequently, an aluminum conductor and a vacuum interrupter were molded by the nano- and micro-filler mixed composites for the first time in nanocomposite research.

Nano- and micro-filler combination enabling practical use of nanocomposite insulating materials

Recent interests concerning nanocomposites are shifting emphasis from fundamental research to application-oriented research. In this study, nano- and micro-filler mixed composites were made and evaluated toward practical use of nanocomposite insulating materials. Some kinds of the nano-filler/micro-filler combinations such as nano-layered silicate/micro-silica, nano-silica/micro-silica and nano-titania/micro-silica were compared from viewpoints of volume resistivitiy, relative permittivity, thermal expansion and insulation breakdown properties. Comprehensive consideration based on experimental results determined a candidate nano- and micro-filler mixed composites to make trial models. An aluminum conductor and a vacuum interrupter were molded from the nano- and micro-filler mixed composites for the first time in nanocomposite research.

Effects of Lignin Derivatives on Cross-Link Density and Dielectric Properties in the Epoxy-Based Insulating Materials for Printed Circuit Boards

Bio-plastics are made from renewable biomass sources. We focus on lignin and develop epoxy resins containing lignin derivatives. We describe the preparation and application of epoxy resin containing lignin as a matrix. Soda-lignin (SLG) is obtained from black liquor in a soda pulp process. First, we use a lignin manufacturing process in which a methanol extraction method enabled reduction in the molecular and hydroxyl equivalent weights of lignin and removal of SiO2 and cellulose. Second, we investigate the ratio of diglycidyl ether of bisphenol-A (DGEBA) and methanol extraction SLG (me-SLG). From the viewpoint of cross-linking density and dielectric properties, 100/84 phr in the DGEBA/me-SLG casting system is found to be preferable. Finally, we try to fabricate an insulating material made up of DGEBA/me-SLG for an aluminum-based printed circuit board, and it achieves standard values.

Nano-clay and micro-silica mixed composites for insulating materials for environmentally-conscious switchgear

Nano-clay and micro-silica mixed composites were made for use as insulating materials for switchgear. Observation of nano-clay dispersion and measurements of insulation breakdown properties under a homogeneous electric field were conducted of these composites. Moreover, simulations were carried out to estimate the curing reaction and rheological behavior of the composite in an automatic pressure gelation system. Experimental results demonstrated that these composites have suitable material characteristics for practical use in switchgear.

Component models insulated with nanocomposite material for environmentally-friendly switchgear

Nano-clay and micro-silica mixed composites were made for use as insulating materials for environmentally-friendly switchgear. The thermal properties and V-t characteristics of these composites were evaluated under a homogeneous electric field. They were shown to have sufficient thermal and insulation breakdown properties as insulating materials for switchgear. In particular, their average insulation breakdown time was longer than that of conventional filled epoxy at 10 and 20 kV/mm. Moreover, we succeeded in making component models insulated with the composite for switchgear.

Application-oriented researches on nanocomposite insulating materials

In the past decade, the nanocomposite technology has made much progress rapidly. We also developed the epoxy-based nanocomposites which have the enhanced insulation properties. The advantages of the nanocomposite materials stimulate the efforts for practical use of them. Therefore, the applications of the nanocomposite materials are primary interests in current researches. In this paper, we briefly introduce the four kinds of the application-oriented researches on the nanocomposite insulating materials.

Development of epoxy resins modified with lignocellulosic biomass for insulating materials

In recent years, the use of biomass resources attracts attention from the problem of global warming and exhaustion of petroleum. The lignocellulose is one of the major materials of biomass. Lignocellulose composed lignin and cellulose is the main conponent of wood. We developed the epoxy-based bioplastic derived from lignocellulosic materials in the viewpoint of not only environmental friendliness but also functional advancement. In this presentation, we describe the effects of lignocellulose derivatives added to the properties of epoxy resin.