WACKER at ECS: Presents VAE Dispersion for Difficult-to-Bond Surfaces in Paper & Packaging Applications

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

Determining the tensile lap-shear strength of a wood-aluminum bond formulated with the new GENIOSIL XB binder. The new hybrid polymers enable the formulation of high-strength structural adhesives. Such adhesives are free of isocyanates and solvents and offer excellent adhesion to wood, glass, metals and ceramics even without a primer.

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 close-meshed 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 in-compatibilities 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

WACKERs 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 re-emulsifies 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.

About WACKER

WACKER is a globally active chemical company with some 16,300 employees and annual sales of around ?.63 billion INSERT INTO [lzx].[dbo].[tb_new]([id],[type],[title],[source],[personal],[image],[contents],[time],[number]) VALUES (2012). WACKER has a global network of 24 production sites, 21 technical competence centers and 53 sales offices.