Patent ID: 9212089
Filing Date: 2015-12-15
Classification: B05D,C03C

Abstract:
1. A process for applying an optical coating to a substrate comprising the steps of: (a) preparing an optical coating formulation comprising a solvent component and a film forming component; (b) using a die coater comprising a slot die to form a coated substrate by applying the optical coating to a substrate, where the applied optical coating forms a wet film thereon having a wet film thickness from 8 μm to 100 μm; (c) drying the coated substrate, where the coated substrate is in a substantially horizontal plane thereby converting the wet film to a dry film having a dry film thickness of more than 20 nm and less than 500 nm; and, optionally (d) curing the coated substrate, wherein the optical coating formulation comprises greater than 0.3 wt % to no more than 5 wt % solids relative to the total weight of the optical coating formulation; and wherein the slot die comprises a slot gap defined by an upstream lip and a downstream lip, the upstream lip being positioned upstream from the flow of the optical coating and having a lip thickness of 0.15-5 mm and the downstream lip being positioned downstream from the flow of the optical coating and having a lip thickness of 0.15-2 mm, and wherein the slot gap is in the range of 1.1 to 9 times the thickness of the wet film, and wherein a coating gap of at least 20 μm is defined between the downstream lip distal to the slot gap and the substrate, and establishes a ratio of the coating gap to the wet film thickness of at most 15.