SiOxCy Coated Glass Substrate Resisting Chemical Degradation
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Solution Overview
Problem
Soda-lime glass products, especially in outdoor and high-humidity applications, face issues with chemical resistance and optical neutrality, as existing coatings either compromise light transmission properties or introduce unwanted yellow edge colors.
Innovation Solution
A SiOxCy coating deposited by chemical vapor deposition, using a gaseous mixture of monosilane, carbon dioxide, and ethylene, is applied to glass substrates, providing enhanced chemical resistance while maintaining neutral optical properties and avoiding yellow edge colors, with a thickness between 10 nm and 50 nm and a C/Si atomic ratio between 0.1 and 0.8.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diamond-like coatings (DLC) are used to increase chemical resistance, then chemical resistance is improved, but optical properties deteriorate with yellow or brown edge color
Solution Approach 1:
The patent changes the chemical composition parameters of the coating by incorporating carbon along with silicon and oxygen, creating a SiOxCy composition rather than traditional DLC. This compositional parameter change allows the coating to maintain chemical resistance while improving optical transparency and reducing yellow edge coloration.
Solution Approach 2:
The patent creates a composite coating material combining silicon, oxygen, and carbon in specific ratios (SiOxCy where 1.5 < x/y < 3). This composite material integrates the protective properties of silica with the optical properties of carbon-containing materials, achieving both chemical resistance and neutral optical appearance.
2Reliability
If magnetron sputtered aluminum doped silica coatings are applied to improve chemical resistance, then chemical resistance is improved, but production cost increases due to low deposition rates and required heat treatment
Solution Approach 1:
The patent replaces the mechanical sputtering process with chemical vapor deposition (CVD). This substitution enables higher deposition rates and eliminates the need for subsequent heat treatment, as the CVD process directly forms the coating at appropriate temperatures during the deposition itself.
Solution Approach 2:
The patent changes the deposition method parameters from room temperature sputtering to elevated temperature CVD, which enables faster deposition rates and direct formation of the protective coating without requiring post-deposition heat treatment, thereby improving productivity.
3Productivity
If silica based coatings are deposited by CVD using monosilane and strong oxidizer, then deposition efficiency is improved, but powder formation occurs causing clogging and coating defects
Solution Approach 1:
The patent introduces carbon as an intermediary substance that moderates the reaction between monosilane and oxygen. The carbon prevents direct premature oxidation of monosilane in the gas phase, eliminating powder formation while still allowing efficient deposition of the SiOxCy coating on the substrate.
Solution Approach 2:
The patent converts the potentially harmful high reactivity of monosilane with strong oxidizers into a beneficial process by using carbon to control the reaction sequence. The carbon first reacts with oxygen, preventing monosilane oxidation in the gas phase, then the controlled deposition proceeds without powder formation, turning a reactive hazard into a controlled advantage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The SiOxCy coating significantly increases the chemical resistance of glass substrates, maintains neutral optical properties, and prevents the appearance of yellow edge colors, even after heat treatment, with haze levels below 0.5% in various chemical and mechanical tests, and meets durability standards.
Implementation Method 1
A SiOxCy coating deposited by chemical vapor deposition, using a gaseous mixture of monosilane, carbon dioxide, and ethylene, is applied to glass substrates
Implementation Method 2
using a gaseous mixture of monosilane, carbon dioxide, and ethylene, is applied to glass substrates
Data Source
AI summary
The invention relates in an embodiment to a glass substrate with increased weathering and chemical resistance where a surface bears a SiOxCy coating wherein the O/Si atomic ratio is comprised between 1.75 and 1.95 and the SiOxCy coating thickness is comprised between 10 nm and 80 nm. Other embodiments relate to glazings having a glass substrate where a surface bears a SiOxCy coating wherein the O/Si atomic ratio is comprised between 1.2 and 1.95 and the SiOxCy coating thickness is comprised between 10 nm and 80 nm.