Silane-based glues have an interesting history and versatile properties that have made them popular in various markets. Modified silane-based adhesives, initially developed in Japan during the 1980s, serve as an alternative to traditional polyurethane adhesives. These adhesives are well-regarded for their elastic characteristics and have gained recognition in both European and American markets.
Modified silane-based adhesives are one-component glues that undergo a curing process called polycondensation, which involves the emission of methanol. Once cured, these adhesives possess the strength and elasticity akin to elastomeric materials. There are two main types of modified silane adhesives: polyether-modified silanes and polyurethane-modified silanes, also known as hybrid polyurethanes. Polyether-modified silanes tend to be more resistant and elastic compared to their polyurethane-modified counterparts.
Some typical properties of modified silane adhesives include their mechanical and chemical characteristics: Mechanical characteristics:
- Elasticity and flexibility
- Tensile strength ranging from 1 to 4 MPa, with silane-modified epoxy achieving up to 8 MPa
- Maximum elongation of 100% to 300%
- Excellent resistance to ultraviolet rays
- Ability to be painted, even shortly after application (wet on wet)
- Adhesion to a wide range of materials, such as metal, ceramic, and plastic, without the need for primers or activators
- Absence of isocyanates, reducing health risks