Halogen-Containing Aminimide Compounds as Tire Cord Adhesives

Abstract

Abstract Aminimides derived from dibasic acids such as sebacic acid have proven to be very good adhesives when used in the first dip of a two-dip tire cord system. These aminimide materials have the advantage of being water soluble for easy application. They give effective adhesion of rubber to polyester tire cord. Although they offer process advantages, their performance is only approximately as good as present commercial art. It would be a further advantage if aminimides for tire cord bonding were improved over the best tire cord adhesive. Consequently, a means to effect bonding improvement was sought. Halogenated aminimides were prepared to effect tire cord bonding improvement to polyester cord. Various compounds derived by synthesis procedures for polyhalo aromatic or norbornene aminimide compounds were prepared. The preparations were designed so that the starting materials were readily available. The aminimide precursors avoided base-displaceable halogen because strong base is needed to make aminimides. Thus, aliphatic halogenated starting materials were not used because they contain base-displaceable halogen. Two of the model aminimides prepared were polyhalo aromatic aminimides and five were polychloronorbornene nuclear or side chain aminimides. In a two-dip system, aminimide compounds derived from hexachlorocyclopentadiene showed adhesion values of up to 164.6 newtons and 100% rubber coverage remaining after extracting the polyester cord from the rubber test specimen. This was equal to the best aminimide dibasic acid polyester tire cord adhesion and coverage. But although the bonding with the halogen-containing aminimides was good, the goal of improved adhesion was not met. Although the chlorinated compounds of this study were promising in bonding rubber to polyester tire cords, the first ones lacked water solubility. Water solubility is considered desirable from the process dip viewpoint. A water soluble version was made where each of two of the chlorine atoms were replaced by a methoxy group. However, tire-cord-to-rubber bonding tests of the water-soluble version of the polyhaloaminimide type was not found to be an improvement over the several oil-soluble versions prepared and tested.