At the World Adhesive and Sealant Conference (WAC) 2012 from September 18 to 21 in Paris, France, Wacker will unveil its new Geniosil XB product range for high-strength structural adhesives. Based on alpha-silane technology, they cure on contact with atmospheric moisture to form thermosets and achieve the high Shore-D strength needed for structural adhesives. They also have no known health risks, meet high technical requirements and give manufacturers wide scope for formulation. Another highlight is Vinnapas EP 8010: The new dispersion, based on vinyl acetate- ethylene copolymers (VAE), reliably and permanently bonds paper to challenging surfaces such as polyvinyl chloride (PVC), polyester or polystyrene. It is also characterized by outstanding heat resistance and very high setting speed.
The Geniosil XB product line is a range of alpha-silane-terminated polyethers. The polymers are of low viscosity and feature a high density of crosslinkable silyl groups. Consequently they form a closemeshed three-dimensional network as they cure. Depending on the formulation, hardnesses in the high Shore-D range develop, which, in the past, have not been possible with silane-terminated polyethers. And their low viscosity makes the new hybrid polymers easy to handle and process. In particular, they can be formulated without plasticizers, solvents or the use of tin catalysts – an advantage that is the result of alpha silane technology. Tin-free formulations eliminate incompatibilities with ester-based additives, thereby widening the formulation scope and enhancing the shelf life of the adhesive.
Adhesives formulators can modify the mechanical end properties and the adhesive strength in the formulation for precise adjustment in line with requirements. In terms of adhesive strength and flexibility, the cured adhesives are making advances into what used to be the exclusive domain of epoxy-based, isocyanate-curing systems. Depending on the substrate, adhesives formulated using GENIOSIL® XB can attain adhesive strengths of up to 15 N/mm2. A one-centimeter spot bond between two beechwood blocks can withstand loads up to
120 kg. GENIOSIL® XB is also suited for making waterproof wood adhesives that satisfy durability classes D1 through D4 (EN 204).
The new binder technology makes structural adhesives especially easy to use. They cure without blistering and gain strength quickly; they adhere to many commonly used materials such as wood, glass, metals and ceramics with no need for primers. Adhesives based on
GENIOSIL® XB can be applied and processed just like conventional
polyurethane-based products.
