CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage of International Application No. PCT/EP2017/055681, filed Mar. 10, 2017, which claims the benefit of European patent Application No. 16159974.1, filed Mar. 11, 2016, the entire contents of which are incorporated herein by reference.

The invention relates to the use of heat resistant materials as adhesives, certain compositions of hybrid materials and inorganic sols and use thereof as sealing materials and corrosion protection layers.

Metallic components and materials are used in the industrial field and also in the private household in many different fields in which protection against corrosion is to be achieved or the ageing process of the workpiece prevented or retarded. As well as to the most diverse weather conditions, these components are exposed to environments which represent a particularly demanding chemical and physical stress for the coating materials and materials used. Particularly in presence of corrosive media and in combination with alternating thermal stresses or high pressure stresses, an increased requirements profile is set for the materials used.

Independently of their use location and the particular application, unprotected medium-carrying systems are subject to corrosion processes which damage the material used and are attended by high repair expenditure. The corrosion of the pipe systems leads annually to high financial losses which arise through repairs and maintenance works. Particularly with pipe systems which carry chemical compounds harmful to nature and the environment, corrosion can lead to immense economic damage occurring in addition to financial damage.

In the field of the bonding of metallic and other materials, a great variety of polymer-type adhesive systems are used. In this, the purpose is to bond workpieces to one another temporarily or permanently. The currently available adhesive classes distinguish between non-curing adhesives, physically curing adhesives and chemically curing adhesives. To the class of the non-curing adhesives or the bonding adhesives also described as binders, are assigned in particular high viscosity polymer systems which are applied as mostly solvent-free low viscosity systems and brought into the adhesive state by means of UV or thermally. Such materials used for example in the aviation industry display good strength, but are only thermally stable up to ca. 200-220° C.

The class of the physically curing adhesives includes plastisols, hot-melt adhesives, solvent-based adhesives and dispersions. These are on the on hand solvent-containing systems (contact adhesives), which are macromolecular but chemically not crosslinked. The viscosity of the materials is lowered by addition of solvent and the contact adhesives are applied onto both adherends. The plastisols are in particular used in vehicle construction and these adhesives are polymers dispersed in solvents, such as polyvinyl chloride. Just like the hot-melt adhesives, depending on the application field, these adhesives also show good adhesive properties, but the thermal stability lies in the range from only 120 to 150° C.

The chemically curing adhesives include the one-component (low molecular weight, plasticizing substances based on phenol or epoxy resins, polybenzimidazoles or polyimides), the two-component (polyester, cold-curing epoxy resins, acrylate adhesives and urethanes) and the cold-curing materials (methacrylates and silicone resins). These adhesives also show good adhesive properties and to some extent high deformation strengths. However, here also the maximum temperature resistance lies in the region of 200° C.

From the prior art, it is clear that many compositions are available for the bonding of metallic materials. However, no materials are known which have both a high temperature resistance >250° C. and also can be used as adhesive for example for the production of laminate structures. At the same time, it is not known that the adhesive systems can also be used as corrosion protection layers or sealing materials

The invention is therefore based on the problem of providing materials which are suitable as adhesives, in particular for metals, and have a high temperature resistance, preferably >250° C.

Surprisingly, it was now found that certain organic, inorganic and hybrid materials are suitable as adhesives, in particular as metal-metal adhesives. Explicitly, it was established that these materials can be used for thermally demanding applications, in which in particular two metal workpieces or one metal workpiece are to be permanently bonded to a plastic component.

