Waterproofness results for the surface treatment of heavy-duty leather for adhesion enhancement

This article presents further work undertaken in respect to the use of specific primers for adhesion on leather surfaces. This research focused on the use of photoreactive reagents and silane networks as primers and investigated their roles in seam strength and resistance against water ingress. A specific waterproof test was undertaken on treated samples in accordance with EN ISO 5403:2002. Samples treated with 4-(2,2 '-iminodiethanol)-3-nitrophenylazide (azide 4) when primed only on one side of the test panel showed good resistance to water ingress. Samples treated with 3,5-dihydroxyphenyl-4-azidobenzoate (azide 7) or 3-(2-aminoethylamino) propyltriethoxysilane (AEAPES) on both sides of the test panels resulted in a seam that did not fail. However, double side treatment with these reagents generated a thicker glue line than single side treatment, which might present practical problems in terms of the flexibility of the resultant assembly during its life cycle.