WACKER presents Hybrid Polymers for High- Strength Structural Adhesives and VAE Dispersion for Difficult-To-Bond Surfaces in Paper and Packaging Applications

At the European Coatings Show (ECS) 2013 from March 19 to 21 in Nuremberg, WACKER will unveil its 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 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.

Reliable Bonding to Difficult Surfaces

WACKER’s new VINNAPAS® EP 8010, an aqueous dispersion based on vinyl acetate-ethylene copolymers, offers exceptional adhesive

properties for demanding paper and packaging applications. It was developed specifically to bond difficult surfaces, such as printed and coated papers to polymeric film made of polyvinyl chloride (PVC), polyester or polystyrene. These are particularly challenging to bond because their surfaces are difficult to wet with the adhesive, making it hard to obtain a stable join.

Now, the novel VINNAPAS® EP 8010 offers excellent adhesion to a wide range of difficult surfaces, and can be readily applied by machine.

At the same time, it shows outstanding setting speed and produces a highly heat-resistant bond. VINNAPAS® EP 8010 reemulsifies fast, thus facilitating cleaning of the application equipment. The polyvinyl-alcohol-stabilized dispersion also scores with its broad formulation scope.

In addition to its exceptional adhesive properties, VINNAPAS® EP 8010 is characterized by its environmental and user-friendly properties. For example, it enables the formulation of plasticizer-free adhesives, thereby keeping the migration potential in the adhesive extremely low. Another advantage is that the dispersion is manufactured without the use of alkylphenol ethoxylates (APEO).

The new dispersion, which belongs to the VINNAPAS® Plus class for especially demanding product solutions, is thus ideal for formulating adhesives used in high-performance paper and packaging applications, such as food-packaging bags and up-market folding boxes for exclusive consumer goods, or in laminated products for car interiors.

Visit WACKER at ECS 2013 in Hall 1, Booth 1-510.