Dynasylan® 1122 is a bifunctional organic compound in which the silicon-functional ethoxy-groups hydrolyze in the presence of water to form reactive silanols, which can be bonded to an inorganic substrate; the organophilic amino group can interact with a suitable polymer. Due to 6 hydrolyzable substituents present in one molecule, Dynasylan® 1122 is exceptionally suitable to form highly crosslinked networks on and between substrates and in organic matrices.
The hydrolysis of Dynasylan® 1122 in water takes place by acidic catalysis (e.g. formic or acetic acid at a pH of 2-3). In order to achieve solubility in organic solvents simply add 2-4 wt.-% of water per wt.-% of Dynasylan® 1122. Upon stirring for 5h the solutions are ready for use.
Examples of suitable inorganic substrates are glass, glass fibres, glass wool, mineral wool, silicic acid, quartz, sand, cristobalite, wollastonite and mica; also suitable are aluminium hydroxide, kaolin, talc, other silicate fillers, metal oxides and metals. Examples of suitable polymers are epoxy resins, polyurethanes, phenolic resins, furan resins, melamine resins, PA, PBT, PC, EVA, modified PP, PVB, PVAC, PVC, acrylates and silicones.
The secondary amino group in Dynasylan® 1122 provides high basicity at somewhat lower reactivity compared to primary amino groups. This is of major advantage in e.g. adhesives and sealants where the silane is added to the polymer matrix: Homogeneous distribution and bonding/networking of Dynasylan® 1122 to the inorganic filler can commence unless bonding to organic materials (e.g. polymers) will proceed.
Moreover, Dynasylan® 1122 has been successfully used as a component in aqueous PA- and PU-sizes for glass fibers.
Typical Applications
Examples are:
- glass fiber/glass fabric composites: as size constituent or finish
- metal primers
- mineral fiber insulating materials, abrasives: as additive to phenolic resin binders
- foundry resins: as additive to phenolic, furane and melamine resins
- adhesives and sealants: as primer or additive
- mineral-filled polymers (composites) or HFFR cables: for pretreatment of fillers and pigments
- paints and coatings: as additive and primer for improving adhesion to the substrate
Benefits at a glance
- improvement in product properties, such as
- flexural strength, tensile strength, impact strength and modulus of elasticity
- moisture and corrosion resistance
improvement in processing properties, such as
- adhesion
- filler dispersion
- rheological behaviour: reduction in viscosity, Newtonian behaviour
- higher degree of filling