English Abstract

Direct Adhesion between Rubber and Other Materials

Takashi KAKUBO
Yokohama Rubber Co., Ltd., Hiratsuka, Kanagawa, Japan
Nippon Gomu Kyokaishi,(2017),90(5),243-249 General Review in Japanese

Strong adhesion between rubber and steel cords is essential for tires, pressure resistant hose, conveyor belt and so on to exhibit a good performance. Therefore, many studies have been carried out to clarify the adhesion mechanism between rubber and steel cords. It has been recognized that the rubber/brass plated cord interface is composed of some layers, such as cupper sulfide, zinc oxide and zinc sulfide. Although photoelectron spectroscopy (PES) is often used to observe such adhesive interfaces, it is difficult to expose the strongly adhered layers.
In this report, two studies which examine buried interfaces of rubber/brass systems are introduced. One is a study applied synchrotron PES to analyze the formation process of the adhesive interlayer during vulcanization by using socalled a filter-paper method. At least five sulfur- containing species are identified in the adhesive interlayer including CuS and CuxS (x≃2). Formation of CuxS (x≃2) in the adhesive layer is observed at the very beginning of vulcanization. Then CuxS (x≃2) chemically changes to CuS due to a presence of excess sulfur. The other is a study applied HAXPES (Hard X-ray Photoelectron Spectroscopy) to directly observe the buried interfaces. Excess sulfur is observed in the model of the exposed interface prepared by the filter-paper method in comparison with an actual rubber/brass interface.

Keywords: Photoelectron Spectroscopy, Synchrotron, Rubber, Brass, Adhesion, Copper Sulfide, HAXPES