For many years ophthalmic coatings with the best abrasion resistance have been thermal cured coatings containing solvent. These coatings were generally based on polysiloxanes with nano particles of silicon dioxide dispersed in the mix. The polysiloxanes were produced from epoxy functional silanes, with varying percentages of other silanes to modify the properties to give the best balance of abrasion resistance, adhesion, and AR compatibility.
Advantage’s of a coating containing polysiloxane is superior abrasion resistance and enhance adhesion between the hard coat and the first layer of the AR stack. This is due in part to a chemical bond between the hard coat and the first layer of the AR stack. It is well documented that polysiloxanes typically provide superior adhesion to minerals.
A disadvantage of a typical polysiloxane coating is poor stability in a solvent free system. The use of polysiloxanes in UV cured Ophthalmic Coatings has been criticized in various publications as leading to poor stability in a solvent free system. See for example Patent Application number US 2009/0311518 A1.
Ultra Optics has long been working with silanes, having first developed a thermal coating based on silane technology. Since then Ultra Optics has developed polysiloxane coatings with excellent stability, but primarily aimed at the tintable backside coating market.
After much research, Ultra Optics is utilizing Advanced Silane Technology (AST) to create superior abrasion resistance and adhesion in UV solvent free coatings.
AST-1 is a UV, solvent free, non-tintable, first generation AST coating developed for maximum performance. AST-1 provides superior abrasion resistance, adhesion, film clarity and AR enhancement. It is a perfect hardcoat compliment to premium lens technology.
With Advanced Silane technology, Ultra Optics is taking backside UV coating from the simplicity of the past to the science of the future.