Antireflective Coating Curing at Ambient Temperature

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Solution Overview

Problem

Existing antireflective coatings for glass require high-temperature sintering above 500 °C for mechanical stability, making it impractical to apply on already installed glass substrates like solar panels or greenhouse panels, which need a coating that can cure at ambient conditions and provide long-term antireflective and mechanical stability.

Innovation Solution

An antireflective coating composition comprising hydrophilic spherical and elongated silica nanoparticles in specific ratios, along with a polysilicate and water as a solvent, capable of curing between 3 to 50 °C, allowing for on-site application on glass substrates without the need for elevated temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high-temperature sintering above 500 °C is used to achieve mechanical stability, then the coating provides long-term mechanical stability, but the coating cannot be applied on already installed glass substrates and requires complex high-temperature processing

Engineering Contradiction:
Improvemechanical stabilityVSAvoidapplication feasibility
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent changes the curing temperature parameter from above 500 °C to ambient temperature (3-50 °C) by modifying the coating composition to include specific nanoparticles and curing agents that enable low-temperature curing, thereby making the coating applicable to already installed glass substrates while maintaining mechanical stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite coating material comprising hydrophilic spherical and elongated silica nanoparticles, organic compounds, and water, which enables the coating to cure at ambient temperatures and be applied to already installed glass substrates while providing long-term mechanical stability and antireflective properties

Inventive Principle:
Principle #40Composite materials

2Reliability

If high-temperature sintering above 500 °C is used to achieve mechanical stability, then the coating achieves durable performance, but the processing complexity and energy consumption increase

Engineering Contradiction:
Improvelong-term stabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent changes the curing temperature parameter from above 500 °C to ambient temperature (3-50 °C), dramatically reducing energy consumption while maintaining the long-term stability and reliability of the coating through optimized nanoparticle composition and curing mechanisms

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If conventional antireflective coating composition is used, then the coating provides antireflective properties, but the coating lacks mechanical stability at ambient temperatures and requires high-temperature curing

Engineering Contradiction:
Improvelight transmissionVSAvoidmechanical stability
Core Design Contradiction:
Illumination intensityVSStrength

Solution Approach 1:

The patent uses a composite coating material comprising hydrophilic spherical and elongated silica nanoparticles, organic compounds, and water, which enables the coating to provide both antireflective properties and mechanical stability at ambient temperatures, eliminating the need for high-temperature curing

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the coating composition parameters by incorporating specific ratios of spherical and elongated silica nanoparticles along with curing agents, enabling the coating to achieve mechanical stability and antireflective properties at ambient temperatures rather than requiring high-temperature processing

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If the coating composition is designed for on-site application on already installed glass, then the coating can be applied easily at ambient temperature, but the coating may lack the mechanical stability required for long-term durability

Engineering Contradiction:
Improveapplication simplicityVSAvoidmechanical stability
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent changes the curing temperature parameter to ambient temperature (3-50 °C) and optimizes the nanoparticle composition and curing agent ratios to ensure that the coating achieves both ease of application and long-term mechanical stability without requiring high-temperature processing

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite coating material with specifically ratios of hydrophilic spherical and elongated silica nanoparticles, organic compounds, and water, which enables the coating to be applied easily at ambient temperatures while achieving the mechanical stability required for long-term durability on already installed glass substrates

Inventive Principle:
Principle #40Composite materials

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 coating composition achieves mechanical stability and antireflective properties at ambient temperatures, enhancing light transmission and hydrophilicity, with improved shelf-life and ease of application, suitable for solar panels and greenhouse glass panels.

Implementation Method 1

The optical function of such an antireflective coating is generally achieved by the effective refractive index of the coating being lower than that of the substrate. This leads to a gradient of the refractive index of air to the refractive index of the substrate. Thus, the amount of light reflected from the coated substrate is reduced.

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

the coating composition is capable of curing at a temperature in the range of from 3 to 50 °C

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Data Source

PatentEP3359606B1Room temperature curing highly durable Anti-reflective coating containing nanoparticles
Publication Date: 2020.08.19 3M INNOVATIVE PROPERTIES CO

AI summary

In one aspect of the present disclosure, there is provided an antireflective coating composition comprising (a) hydrophilic spherical silica nanoparticles; (b) hydrophilic elongated silica nanoparticles, wherein the coating composition exhibits a pH-value in the range of from 7 to 12.5 and the ratio between the hydrophilic spherical silica nanoparticles (a) and the hydrophilic non-spherical silica nanoparticles (b) is in the range of from 10:1 to 1:10. In a further aspect of the present disclosure there is provided a method for coating a substrate, comprising the steps (i) providing a substrate having at least one surface; (ii) providing the antireflective coating composition according to the present disclosure; (iii) coating the substrate on at least one surface; (iv) drying the coating, thereby obtaining a coated substrate, wherein step (iv) is carried out at a temperature in the range of from 5 °C to 300 °C.