ゴムと黄銅めっきスチールコードとの接着におけるヘキサメトキシメチルメラミン(HMMM)の影響

抄録

A resorcinol-formaldehyde (RF) resin is typically formulated in a compound for steel cord coating in order to improve the brass-rubber adhesion in the interface. A hexamethoxymethylmelamine (HMMM) is also formulated to accelerate the condensation reaction in the RF resin. Our study found that formulation of HMMM in the absence of RF resin has an ability to trap amines generated from N, N'-dicyclohexylbenzothiazole-sulphenamide(DCBS) accelerated vulcanization system, which prevents stress-induced corrosion crack in the brass layer at the brass plated steel cord. In this study, the nature of HMMM formulation was thoroughly investigated.
It was clarified that the physical properties of the vulcanized rubber such as crosslink density and strain modulus are effectively improved by trapping the residual amine component. When the RF resin was used in conjunction with the HMMM, the process of such amine-trap is tremendously interrupted due to the preferential consumption of the RF resin at condensation. However, the HMMM begins to trap the amine immediately after the complete of condensation reaction even during the formulation with the RF resin. It was revealed by ASTM pull-out test that the adhesion property is greatly improved by trapping the residual amine.