Multilayer Barrier Stack with Thiol-Ene Smooth Layer

The barrier coating is divided into multiple functional layers including a thiol-ene smooth layer, a barrier layer, and optional intermediate layers. Each layer performs a specific function: the thiol-ene layer provides smoothness and adhesion, the barrier layer provides oxygen and water vapor barrier, and intermediate layers provide transition and additional barrier functions. This segmentation allows each layer to be optimized for its specific purpose, achieving superior overall barrier performance.

The patent employs composite material structures combining different materials with complementary properties. The thiol-ene polymer matrix provides flexibility and adhesion, while embedded inorganic particles (such as silica, alumina, or titania) provide enhanced barrier properties and scratch resistance. The combination of organic and inorganic materials creates a synergistic effect that neither material could achieve alone.

Different layers are designed with locally optimized properties: the thiol-ene smooth layer provides scratch resistance and surface smoothness where needed, while the barrier layer provides oxygen and water vapor barrier where required. The intermediate layers provide transition zones that maintain adhesion and flexibility. This local quality optimization allows each layer to excel at its specific function without compromising overall performance.

The thiol-ene smooth layer incorporates inorganic particles (such as silica, alumina, or titania) embedded in the polymer matrix to create a composite structure that provides both scratch resistance and barrier properties. The thiol-ene polymer provides flexibility and adhesion, while the inorganic particles provide hardness and barrier properties, creating a synergistic composite that addresses both scratch resistance and barrier performance requirements.

The inorganic particles are pre-dispersed in the thiol-ene monomer mixture before curing, creating a homogeneous composite coating solution. This preliminary dispersion ensures uniform particle distribution throughout the coating layer, which provides consistent scratch resistance across the entire surface. The pre-mixed formulation simplifies the manufacturing process by eliminating the need for complex particle incorporation steps during coating application.

The patent optimizes particle size parameters (typically 0.1-10 micrometers) and particle concentration (5-50 wt%) to achieve the desired scratch resistance while maintaining manufacturability. By controlling these parameters, the coating formulation maintains appropriate viscosity for application while providing sufficient particle reinforcement for scratch resistance. The thiol-ene curing process transforms the liquid composite into a solid, scratch-resistant coating in a single step.