Foamed Opacifying Layer Composition for Single-Coat Light-Blocking
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Solution Overview
Problem
Existing light-blocking materials require multiple coating operations, are heavy, and prone to fugitive carbon black spreading during handling, which affects their durability and aesthetic properties.
Innovation Solution
A method involving a foamable aqueous composition with porous particles, a binder material, surfactants, and opacifying colorants, aerated to create a foamed layer on a substrate, dried without substantial curing, then densified and cured to form a single, light-blocking layer with improved adhesion and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple coating operations are used to achieve light-blocking, then opacity is improved, but device complexity and manufacturing time increase
Solution Approach 1:
The patent combines multiple coating operations into a single coating step by using a foamable composition that expands after application. The foam structure allows a single thin coating to provide the light-blocking properties that would otherwise require multiple thick coatings, thereby reducing manufacturing complexity while maintaining opacity.
Solution Approach 2:
The patent utilizes the phase transition of the foamable composition from liquid to foam state after application. This phase transition allows the composition to expand in volume after being applied as a thin layer, creating a thicker effective coating without requiring multiple application steps, thus resolving the contradiction between opacity and manufacturing complexity.
2Illumination intensity
If thick foam coatings are used to block light, then opacity is improved, but weight increases
Solution Approach 1:
The foamable composition undergoes a phase transition from liquid to foam, expanding in volume after application. This allows a thin applied layer to create a thicker effective barrier to light without proportionally increasing weight, as the foam structure incorporates air pockets that provide light-blocking properties with minimal mass addition.
Solution Approach 2:
The foam structure creates a porous material with numerous air pockets distributed throughout the coating. These pores scatter and block light effectively, providing high opacity with minimal material density and weight, thus resolving the contradiction between light-blocking capability and weight.
3Illumination intensity
If carbon black is used for light absorption, then light-blocking is improved, but fugitive carbon spreads during handling causing staining
Solution Approach 1:
The patent uses a composite foamable composition that incorporates carbon black particles within a foam matrix. The foam structure encapsulates the carbon black, preventing it from becoming fugitive and spreading during handling. This composite structure maintains the light-absorbing properties of carbon black while eliminating the staining problem through physical containment within the cured foam network.
Solution Approach 2:
The foamable composition undergoes a phase transition from liquid to cured foam, which encapsulates the carbon black particles during the curing process. This phase transition locks the carbon black in place, preventing it from becoming fugitive and spreading during subsequent handling, thus resolving the staining issue while maintaining light absorption.
4Reliability
If dense non-foamed coatings are used, then durability is improved, but flexibility and adhesion worsen
Solution Approach 1:
The foamable composition undergoes a phase transition from liquid to foam, and then from foam to cured structure. This two-stage phase transition creates a coating that is lightweight and flexible in its foam state but develops durability through the curing process. The cured foam structure maintains flexibility while providing durable adhesion to the substrate, resolving the contradiction between durability and flexibility.
Solution Approach 2:
The foam structure creates a porous network that allows the coating to remain flexible and conform to substrate movements, improving adhesion. Simultaneously, the cured foam structure provides durability through its crosslinked network. The porous structure prevents cracking and maintains flexibility while the cured state ensures durability, resolving the contradiction between these properties.
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 method results in lighter, more flexible, and durable light-blocking materials with enhanced adhesion and reduced fugitive carbon issues, maintaining opacity and aesthetic appeal while minimizing heat absorption.
Implementation Method 1
aerating the foamable aqueous composition to provide a foamed aqueous composition
Implementation Method 2
aerating the foamable aqueous composition to provide a foamed aqueous composition
Implementation Method 3
drying the foamed aqueous composition, without substantial curing of the binder material, to provide a dry foamed composition on the surface
Implementation Method 4
densifying the dry foamed composition to provide a dry opacifying layer
Implementation Method 5
curing the dry opacifying layer in the foamed, opacifying element to convert the (b) binder material to a (b′) matrix material
Implementation Method 6
an opacifying colorant different from all the one or more (c) additives, which opacifying colorant absorbs electromagnetic radiation having a wavelength of at least 380 nm and up to and including 800 nm
Implementation Method 7
at least 0.05 weight % and up to and including 15 weight % of porous particles, each porous particle comprising a continuous polymeric phase and a first set of discrete pores dispersed within the continuous polymeric phase
Data Source
AI summary
A foamed, opacifying element is prepared to have a light-blocking value (LBV) of at least 4. A method is carried out in a specific order with a unique series of steps including: providing a unique foamable aqueous composition; aerating that foamable aqueous composition to a foam density of at least 0.1-0.5 g/cm3; disposing the foamed aqueous composition onto a surface of a porous substrate; drying the foamed aqueous composition without substantial curing of the binder material therein, to provide a dry foamed composition on the surface, without substantial curing; densifying the dry foamed composition to provide a dry opacifying layer in a foamed, opacifying element; and curing the dry opacifying layer in the foamed, opacifying element.