Patent ID: 10301476

Abstract:
The invention relates to a method for obtaining a calcium fluoride (CaF2) sol solution, comprising the steps of providing a calcium precursor in a first volume in a non-aqueous solvent, and adding, in a second volume, 1.85 to 2.05 molar equivalents of anhydrous hydrogen fluoride (nHF) per mole calcium precursor to said first volume, and/or a magnesium additive is added before or after said fluorination with hydrogen fluoride with additional 1.85 to 2.05 molar equivalents of anhydrous hydrogen fluoride (nHF) per mole magnesium additive. Additionally or alternatively at least one metal additive precursor is added before or after the fluorination with hydrogen fluoride wherein an additional amount of hydrogen fluoride (nadHF) is present in the fluorination step. The invention further relates to sol solutions, method of applying the sol solutions of the invention to surfaces as a coating, and to antireflective coatings obtained thereby.