A new concept of metal — resin adhesion using an intermediate layer of SiOx-C

Abstract

A new concept of a gapless and durable metal-resin compound is proposed using a silica-like layer deposited on a roughened metal surface. This so-called “SiO x -C” layer, with a thickness of about 0.1 μm or less, is formed by flame pyrolysis of a silicon compound, e.g. tetraethoxysilane. It contains impurities of carbon compounds as detected by Rutherford backscattering spectroscopy and electron spin resonance spectroscopy. The surface of the metal alloy will be conditioned also by the flame contact as seen by Auger electron spectroscopy. The SiO x -C layer is the basis for a silane coupling agent, which reacts with the OH groups of the silica and the functional groups of the resin. The concept is verified experimentally with compounds of a resin used in prothodontics and precious or non-precious metal alloys. The SiO x -C layer enables formation of a strong and water-resistant metal-resin bond. To explain these results a multilayer model is proposed which contains an interdiffusion layer additional to the prepared coupling layers.