When a harder object scrapes over a coating film and irreversibly distorts or even penetrates the surface, it produces scratches that are visible as linear damage to the surface.
This damage is markedly lowered by increased surface slip, which can be achieved by flow and leveling additives such as TEGO® Glide. Based on organomodified polydimethylsiloxanes, this product causes the scraping object to slip off rather than penetrate the coating film. Smooth surfaces are markedly less susceptible to scratching, and organomodified siloxanes minimize unevenness in the surface, helping the coating form particularly smooth surfaces. The use of NANOCRYL®, NANOPOL®, and NANOPOX® silica nanocomposites lends permanent scratch and abrasion resistance to solvent-borne and UV-curing coating formulations.
Structurally modified AEROSIL® fumed silica grades can be used as additives for increasing the mechanical stability of resins, making it possible to diminish scratches and make surfaces more hydrophobic or oleophobic.
Silane primers or wash-coats are commonly used to treat metal surfaces (especially zinc, aluminum, and magnesium) in order to reduce corrosion. Dynasylan® SIVO 160 applied as a thin coat on the surface of such metals acts as a barrier to the ingress of chloride and water. It is either used as a sealer or as a primer layer on which a further coatings is applied.
A new class of building block material, VESTANAT® EP-M-95, combines Dynasylan® silanes and isocyanate crosslinker technology and is able to react with resins to create highly scratch-resistant binders that are even suitable for use by automotive OEMs in class A surfaces.
DEGALAN M 726®, a cross-linked/spray-dried emulsion polymer, can be used to create a slip and anti-blocking effect on coating surfaces. Beside of the effects indicated, addition of this product also results in slight matting. Methacrylic-based linked beads can be used for creating structured surfaces with lower gloss levels.
ACEMATT® silica matting agents can be used for enhancing surface structure, allowing manufacturers to achieve dedicated gloss values while meeting the most sophisticated transparency requirements. Soft-feel coatings requiring specific haptic properties can be easily achieved using a new technology that combines polydimethylsiloxanes with ACEMATT® particles to give your substrate the perfect grip.
VESTAGON® BF 1320 and 1321 are suitable for decorative transfer print processes based on polyurethane (PUR) powder coatings.
Surfaces treated with coatings based on VESTOSINT® polyamide powders have high flexural strength and elasticity and excellent abrasion resistance; they are also less susceptible to soiling and easier to clean. The powder particles have a shock-absorbing effect and protect the surface from cracking.
The brands and technologies mentioned above are just a few examples of how surface modification products from Evonik can help you take your coatings to a higher performance level.